C語言學習交流

注：這是老版的答案，基本和現(xiàn)在的版本相同，章節(jié)標號不同，因為以前沒有現(xiàn)在的第二章的內(nèi)容

第一章
1.6
main()
{int a,b,c,max;
?printf("input three numbers:\n");
?scanf("%d,%d,%d",&a,&b,&c);
?max=a;
?if(max<b)max=b;
?if(max<c)max=c;
?printf("max=%d",max);
}

第二章
2.3
(1)(10)10=(12)8=(a)16
(2)(32)10=(40)8=(20)16
(3)(75)10=(113)8=(4b)16
(4)(-617)10=(176627)8=(fd97)16
(5)(-111)10=(177621)8=(ff91)16
(6)(2483)10=(4663)8=(963)16
(7)(-28654)10=(110022)8=(9012)16
(8)(21003)10=(51013)8=(520b)16

2.6
aabb??????? (8)cc??????? (8)abc
?????? (7)AN

2.7
main()
{char c1='C',c2='h',c3='i',c4='n',c5='a';
?c1+=4, c2+=4, c3+=4, c4+=4, c5+=4;
?printf("%c%c%c%c%c\n",c1,c2,c3,c4,c5);
}

2.8
main()
{int c1,c2;
?c1=97;c2=98;
?printf("%c? %c",c1,c2);
}

2.9
(1)=2.5
(2)=3.5

2.10
9,11,9,10

2.12
(1)24? (2)10? (3)60? (4)0? (5)0? (6)0

第三章
3.4
main()
{int a,b,c;
?long int u,n;
?float x,y,z;
?char c1,c2;
?a=3;b=4;c=5;
?x=1.2;y=2.4;z=-3.6;
?u=51274;n=128765;
?c1='a';c2='b';
?printf("\n");
?printf("a=%2d? b=%2d? c=%2d\n",a,b,c);
?printf("x=%8.6f,y=%8.6f,z=%9.6f\n",x,y,z);
?printf("x+y=%5.2f? y+z=%5.2f? z+x=%5.2f\n",x+y,y+z,z+x);
?printf("u=%6ld? n=%9ld\n",u,n);
?printf("c1='%c'or %d(ASCII)\n",c1,c1);
?printf("c2='%c'or %d(ASCII)\n",c2,c2);
}

3.5
57
? 5? 7
67.856400,-789.123962
67.856400,-789.123962
?? 67.86 -789.12,67.856400,-789.123962,67.856400,-789.123962
6.785640e+001,-7.89e+002
A,65,101,41
1234567,4553207,d687
65535,177777,ffff,-1
COMPUTER,? COM

3.6
a=3 b=7/
x=8.5 y=71.82/
c1=A c2=a/

3.7
?? 10?? 20Aa1.5 -3.75 +1.4,67.8/
(空3)10(空3)20Aa1.5(空1)-3.75(空1)(隨意輸入一個數(shù)），67.8回車

3.8
main()
{float pi,h,r,l,s,sq,sv,sz;
?pi=3.1415926;
?printf("input r,h\n");
?scanf("%f,%f",&r,&h);
?l=2*pi*r;
?s=r*r*pi;
?sq=4*pi*r*r;
?sv=4.0/3.0*pi*r*r*r;
?sz=pi*r*r*h;
?printf("l=%6.2f\n",l);
?printf("s=%6.2f\n",s);
?printf("sq=%6.2f\n",sq);
?printf("vq=%6.2f\n",sv);
?printf("vz=%6.2f\n",sz);
}

3.9
main()
{float c,f;
?scanf("%f",&f);
?c=(5.0/9.0)*(f-32);
?printf("c=%5.2f\n",c);
}

3.10
#include"stdio.h"
main()
{char c1,c2;
?scanf("%c,%c",&c1,&c2);
?putchar(c1);
?putchar(c2);
?printf("\n");
?printf("%c%c\n",c1,c2);
}

第四章
4.3
(1)0? (2)1? (3)1? (4)0? (5)1

4.4
main()
{int a,b,c;
?scanf("%d,%d,%d",&a,&b,&c);
?if(a<b)
?? if(b<c)
???? printf("max=%d\n",c);
?? else
???? printf("max=%d\n",b);
?else if(a<c)
???? printf("max=%d\n",c);
?else
???? printf("max=%d\n",a);
}
main()
{int a,b,c,temp,max;
?scanf("%d,%d,%d",&a,&b,&c);
?temp=(a>b)?a:b;
?max=(c>temp)?c:temp;
?printf("max=%d",max);
}
?
4.5
main()
{int x,y;
?scanf("%d",&x);
?if(x<1)y=x;
?else if(x<10)y=2*x-1;
?else y=3*x-11;
?printf("y=%d",y);
}

4.6
main()
{int score,temp,logic;
?char grade;
?logic=1;
?while(logic)
?? {scanf("%d",&score);
??? if(score>=0&&score<=100)logic=0;
?? }
?if(score==100)
?? temp=9;
?else
?? temp=(score-score%10)/10;
?switch(temp)
?? {case 9:grade='A';break;
??? case 8:grade='B';break;
??? case 7:grade='C';break;
??? case 6:grade='D';break;
??? case 5:
??? case 4:
??? case 3:
??? case 2:
??? case 1:
??? case 0:grade='E';
?? }
?printf"score=%d,grade=%c",score,grade);
}

4.7
main()
{long int num;
?int indiv,ten,hundred,thousand,ten_thousand,place;
?scanf("%ld",&num);
?if(num>9999) place=5;
?else if(num>999) place=4;
?else if(num>99) place=3;
?else if(num>9) place=2;
?else place=1;
?printf("place=%d\n",place);
?ten_thousand=num/10000;
?thousand=(num-ten_thousand*10000)/1000;
?hundred=(num-ten_thousand*10000-thousand*1000)/100;
?ten=(num-ten_thousand*10000-thousand*1000-hundred*100)/10;
?indiv=num-ten_thousand*10000-thousand*1000-hundred*100-ten*10;
?switch(place)
?? {case 5:printf("%d,%d,%d,%d,%d\n",ten_thousand,thousand,hundred,ten,indiv);
?????????? printf("%d,%d,%d,%d,%d\n",indiv,ten,hundred,thousand,ten_thousand);
?????????? break;
??? case 4:printf("%d,%d,%d,%d\n",thousand,hundred,ten,indiv);
?????????? printf("%d,%d,%d,%d\n",indiv,ten,hundred,thousand);
?????????? break;
??? case 3:printf("%d,%d,%d\n",hundred,ten,indiv);
?????????? printf("%d,%d,%d\n",indiv,ten,hundred);
?????????? break;
??? case 2:printf("%d,%d\n",ten,indiv);
?????????? printf("%d,%d\n",indiv,ten);
?????????? break;
??? case 1:printf("%d\n",indiv);
?????????? printf("%d\n",indiv);
??? }
}

4.8
main()
{long i;
?float bonus,bon1,bon2,bon4,bon6,bon10;
?bon1=100000*0.1;
?bon2=bon1+100000*0.075;
?bon4=bon2+200000*0.05;
?bon6=bon4+200000*0.03;
?bon10=bon6+400000*0.015;
?scanf("%ld",&i);
?if(i<=1e5)bonus=i*0.1;
?else if(i<=2e5)bonus=bon1+(i-100000)*0.075;
?else if(i<=4e5)bonus=bon2+(i-200000)*0.05;
?else if(i<=6e5)bonus=bon4+(i-400000)*0.03;
?else if(i<=1e6)bonus=bon6+(i-600000)*0.015;
?else bonus=bon10+(i-1000000)*0.01;
?printf("bonus=%10.2f",bonus);
}
main()
{long i;
?float bonus,bon1,bon2,bon4,bon6,bon10;
?int branch;
?bon1=100000*0.1;
?bon2=bon1+100000*0.075;
?bon4=bon2+200000*0.05;
?bon6=bon4+200000*0.03;
?bon10=bon6+400000*0.015;
?scanf("%ld",&i);
?branch=i/100000;
?if(branch>10)branch=10;
?switch(branch)
?{case 0:bonus=i*0.1;break;
? case 1:bonus=bon1+(i-100000)*0.075;break;
? case 2:
? case 3:bonus=bon2+(i-200000)*0.05;break;
? case 4:
? case 5:bonus=bon4+(i-400000)*0.03;break;
? case 6:
? case 7
? case 8:
? case 9:bonus=bon6+(i-600000)*0.015;break;
? case 10:bonus=bon10+(i-1000000)*0.01;
? }
?printf("bonus=%10.2f",bonus);
}
?
4.9
main()
{int t,a,b,c,d;
?scanf("%d,%d,%d,%d",&a,&b,&c,&d);
?if(a>b){t=a;a=b;b=t;}
?if(a>c){t=a;a=c;c=t;}
?if(a>d){t=a;a=d;d=t;}
?if(b>c){t=b;b=c;c=t;}
?if(b>d){t=b;b=d;d=t;}
?if(c>d){t=c;c=d;d=t;}
?printf("%d? %d? %d? %d\n",a,b,c,d);
}

4.10
main()
{int h=10;
?float x,y,x0=2,y0=2,d1,d2,d3,d4;
?scanf("%f,%f",&x,&y);
?d1=(x-x0)*(x-x0)+(y-y0)*(y-y0);
?d2=(x-x0)*(x-x0)+(y+y0)*(y+y0);
?d3=(x+x0)*(x+x0)+(y-y0)*(y-y0);
?d4=(x+x0)*(x+x0)+(y+y0)*(y+y0);
?if(d1>1&&d2>1&&d3>1&&d4>1)h=0;
?printf("h=%d",h);
}
第五章? 循環(huán)控制
5.1
main()
{int a,b,num1,num2,temp;
?scanf("%d,%d",&num1,&num2);
?if(num1<num2){temp=num1;num1=num2;num2=temp;}
?a=num1;b=num2;
?while(b!=0)
?? {temp=a%b;
??? a=b;
??? b=temp;}
?printf("%d\n",a);
?printf("%d\n",num1*num2/a);
}

5.2
#include"stdio.h"
main()
{char c;
?int letters=0,space=0,digit=0,other=0;
?while((c=getchar())!='\n')
?? {if(c>='a'&&c<='z'||c>='A'&&c<='Z') letters++;
??? else if(c==' ')space++;
??? else if(c>='0'&&c<='9')digit++;
??? else other++;
?? }
?printf("letters=%d\nspace=%d\ndigit=%d\nother=%d\n",letters,space,digit,other);
}

5.3
main()
{int a,n,count=1,sn=0,tn=0;
?scanf("%d,%d",&a,&n);
?while(count<=n)
?? {tn+=a;
??? sn+=tn;
??? a*=10;
??? ++count;
?? }
?printf("a+aa+aaa+...=%d\n",sn);
}

5.4
main()
{float n,s=0,t=1;
?for(n=1;n<=20;n++)
?? {t*=n;
??? s+=t;
?? }
?printf("s=%e\n",s);
}

5.5
main()
{int N1=100,N2=50,N3=10;
?float k;
?float s1=0,s2=0,s3=0;
?for(k=1;k<=N1;k++)s1+=k;
?for(k=1;k<=N2;k++)s2+=k*k;
?for(k=1;k<=N3;k++)s3+=1/k;
?printf("s=%8.2f\n",s1+s2+s3);
}

5.6
main()
{int i,j,k,n;
?for(n=100;n<1000;n++)
?? {i=n/100;
??? j=n/10-i*10;
??? k=n%10;
??? if(i*100+j*10+k==i*i*i+j*j*j+k*k*k)
???????? printf("n=%d\n",n);
??? }
}

5.7
#define M 1000
main()
{int k0,k1,k2,k3,k4,k5,k6,k7,k8,k9;
?int i,j,n,s;
?for(j=2;j<=M;j++)
?? {n=0;
??? s=j;
??? for(i=1;i<j;i++)
????? {if((j%i)==0)
???????? {n++;
????????? s=s-i;
????????? switch(n)
??????????? {case 1:k0=i;break;
???????????? case 2:k1=i;break;
???????????? case 3:k2=i;break;
???????????? case 4:k3=i;break;
???????????? case 5:k4=i;break;
???????????? case 6:k5=i;break;
???????????? case 7:k6=i;break;
???????????? case 8:k7=i;break;
???????????? case 9:k8=i;break;
???????????? case 10:k9=i;break;
??????????? }
?????????? }
???????? }
????? if(s==0)
??????? {printf("j=%d\n",j);
???????? if(n>1)printf("%d,%d",k0,k1);
???????? if(n>2)printf(",%d",k2);
???????? if(n>3)printf(",%d",k3);
???????? if(n>4)printf(",%d",k4);
???????? if(n>5)printf(",%d",k5);
???????? if(n>6)printf(",%d",k6);
???????? if(n>7)printf(",%d",k7);
???????? if(n>8)printf(",%d",k8);
???????? if(n>9)printf(",%d\n",k9);
???????? }
?????? }
}

main()
{static int k[10];
?int i,j,n,s;
?for(j=2;j<=1000;j++)
?? {n=-1;
??? s=j;
??? for(i=1;i<j;i++)
????? {if((j%i)==0)
???????? {n++;
????????? s=s-i;
????????? k[n]=i;
???????? }
?????? }
??? if(s==0)
????? {printf("j=%d\n",j);
?????? for(i=0;i<n;i++)
???????? printf("%d,",k[i]);
?????? printf("%d\n",k[n]);
????? }
??? }
}

5.8
main()
{int n,t,number=20;
?float a=2;b=1;s=0;
?for(n=1;n<=number;n++)
?? {s=s+a/b;
??? t=a,a=a+b,b=t;
??? }
?printf("s=%9.6f\n",s);
}

5.9
main()
{float sn=100.0,hn=sn/2;
?int n;
?for(n=2;n<=10;n++)
?? {sn=sn+2*hn;
??? hn=hn/2;
?? }
?printf("sn=%f\n",sn);
?printf("hn=%f\n",hn);
}

5.10
main()
{int day,x1,x2;
?day=9;
?x2=1;
?while(day>0)
?? {x1=(x2+1)*2;
??? x2=x1;
??? day--;
??? }
?printf("x1=%d\n",x1);
}

5.11
#include"math.h"
main()
{float a,xn0,xn1;
?scanf("%f",&a);
?xn0=a/2;
?xn1=(xn0+a/xn0)/2;
?do
?? {xn0=xn1;
??? xn1=(xn0+a/xn0)/2;
?? }
?while(fabs(xn0-xn1)>=1e-5);
?printf("a=%5.2f\n,xn1=%8.2f\n",a,xn1);
}

5.12
#include"math.h"
main()
{float x,x0,f,f1;
?x=1.5;
?do
?? {x0=x;
??? f=((2*x0-4)*x0+3)*x0-6;
??? f1=(6*x0-8)*x0+3;
??? x=x0-f/f1;
?? }
?while(fabs(x-x0)>=1e-5);
?printf("x=%6.2f\n",x);
}

5.13
#include"math.h"
main()
{float x0,x1,x2,fx0,fx1,fx2;
?do
?? {scanf("%f,%f",&x1,&x2);
??? fx1=x1*((2*x1-4)*x1+3)-6;
??? fx2=x2*((2*x2-4)*x2+3)-6;
?? }
?while(fx1*fx2>0);
?do
?? {x0=(x1+x2)/2;
??? fx0=x0*((2*x0-4)*x0+3)-6;
??? if((fx0*fx1)<0)
????? {x2=x0;
?????? fx2=fx0;
????? }
??? else
????? {x1=x0;
?????? fx1=fx0;
????? }
??? }
?while(fabs(fx0)>=1e-5);
?printf("x0=%6.2f\n",x0);
}

5.14
main()
{int i,j,k;
?for(i=0;i<=3;i++)
?? {for(j=0;j<=2-i;j++)
????? printf(" ");
??? for(k=0;k<=2*i;k++)
????? printf("*");
??? printf("\n");
??? }
? for(i=0;i<=2;i++)
?? {for(j=0;j<=i;j++)
????? printf(" ");
??? for(k=0;k<=4-2*i;k++)
????? printf("*");
??? printf("\n");
??? }
}

5.15
main()
{char i,j,k;
?for(i='x';i<='z';i++)
?? for(j='x';j<='z';j++)
???? {if(i!=j)
?????? for(k='x';k<='z';k++)
???????? {if(i!=k&&j!=k)
?????????? {if(i!='x'&&k!='x'&&k!='z')
????????????? printf("\na--%c\tb--%c\tc--%c\n",i,j,k);
?????????? }
????????? }
????? }
}
第六章? 數(shù)組
6.1
?#include <math.h>
?#define N 101
?main()
?{ int i,j,line,a[N];
? for (i=2;i<N;i++)? a[i]=i;
? for (i=2;i<sqrt(N);i++)
??? for (j=i+1;j<N;j++)
????? {if(a[i]!=0 && a[j]!=0)
???????? if (a[j]%a[i]==0)
??????????? a[j]=0;????? }
? printf("\n");
? for (i=2,line=0;i<N;i++)
? {? if(a[i]!=0)
?????? {? printf("%5d",a[i]);
????????? line++;? }
???? if(line==10)
?????? {? printf("\n");
????????? line=0;? }
?? }
}

6.2
#define N 10
main()
{int i,j,min,temp,a[N];
?for(i=0;i<N;i++)
?? scanf("%d",&a[i]);
?for(i=0;i<N-1;i++)
?? {min=i;
??? for(j=i+1;j<N;j++)
????? if(a[min]>a[j])min=j;
??? temp=a[i];
??? a[i]=a[min];
??? a[min]=temp;
??? }
?for(i=0;i<N;i++)
?? printf("%5d",a[i]);
}
?
6.3
main()
{float a[3][3],sum;
?int i,j;
?for(i=0;i<3;i++)
?? for(j=0;j<3;j++)
???? {scanf("%f",&sum);
????? a[i][j]=sum;
???? }
?for(i=0;i<3;i++)
?? sum=sum+a[i][i];
?printf("sum=%f",sum);
}

6.4
main()
{int a[11]={1,4,6,9,13,16,19,28,40,100};
?int temp1,temp2,number, end,i,j;
?scanf("%d",&number);
?end=a[9];
?if(number>end) a[10]=number;
?else
?? {for(i=0;i<10;i++)
????? {if(a[i]>number)
??????? {temp1=a[i];
???????? a[i]=number;
???????? for(j=i+1;j<11;j++)
?????????? {temp2=a[j];
??????????? a[j]=temp1;
??????????? temp1=temp2;
?????????? }
???????? break;
???????? }
?????? }
???? }
?for(i=0;i<11;i++)
?? printf("%6d",a[i]);
}

6.5
#define N 5
main()
{int a[N]={8,6,5,4,1},i,temp;
?for(i=0;i<N/2;i++)
?? {temp=a[i];
??? a[i]=a[N-i-1];
??? a[N-i-1]=temp;
??? }
?for(i=0;i<N;i++)
?? printf("%4d",a[i]);
}

6.6
#define N 11
main()
{int i,j,a[N][N];
?for(i=1;i<N;i++)
?? {a[i][i]=1;
??? a[i][1]=1;
?? }
?for(i=3;i<N;i++)
?? for(j=2;j<i;j++)
???? a[i][j]=a[i-1][j-1]+a[i-1][j];
?for(i=1;i<N;i++)
?? {for(j=1;j<=i;j++)
????? printf("%6d",a[i][j]);
??? printf("\n");
?? }
}

6.7
main()
{int a[16][16],i,j,k,p,m,n;
?p=1;
?while(p==1)
?? {scanf("%d",&n);
??? if((n!=0)&&(n<=15)&&(n%2!=0))p=0;
?? }
?for(i=1;i<=n;i++)
?? for(j=1;j<=n;j++)
???? a[i][j]=0;
?j=n/2+1;
?a[1][j]=1;
?for(k=2;k<=n*n;k++)
?? {i=i-1;
??? j=j+1;
??? if((i<1)&&(j>n))
????? {i=i+2;
?????? j=j-1;
????? }
??? else
????? {if(i<1)i=n;
?????? if(j>n)j=1;
????? }
??? if(a[i][j]==0)a[i][j]=k;
??? else
????? {i=i+2;
?????? j=j-1;
?????? a[i][j]=k;
????? }
??? }
?for(i=1;i<=n;i++)
?? {for(j=1;j<=n;j++)
????? printf("%3d",a[i][j]);
??? printf("\n");
?? }
}

6.8
#define N 10
#define M 10
main()
{int i,j,k,m,n,flag1,flag2,a[N][M],max,maxi,maxj;
?scanf("%d,%d",&n,&m);
?for(i=0;i<n;i++)
?? for(j=0;j<m;j++)
???? scanf("%d",&a[i][j]);
?flag2=0;
?for(i=0;i<n;i++)
?? {max=a[i][0];
??? for(j=0;j<m;j++)
????? if(max<a[i][j])
??????? {max=a[i][j];
???????? maxj=j;
??????? }
??? for(k=0,flag1=1;k<n&&flag1;k++)
????? if(max>a[k][maxj])flag1=0;
??? if(flag1)
????? { printf("\na[%d][%d]=%d\n",i,maxj,max);
??????? flag2=1;
????? }
??? }
?if(!flag2) printf("NOT");
}

6.9
#include<stdio.h>
#define N 15
main()
{int i,j,number,top,bott,min,loca,a[N],flag;
?char c;
?for(i=0;i<=N;i++)
?? scanf("%d",&a[i]);
?flag=1;
?while(flag)
?? {scanf("%d",&number);
??? loca=0;
??? top=0;
??? bott=N-1;
??? if((number<a[0])||(number>a[N-1]))
????? loca=-1;
??? while((loca==0)&&(top<=bott))
????? {min=(bott+top)/2;
?????? if(number==a[min])
???????? {loca=min;
????????? printf("number=%d,loca=%d\n",number,loca+1);
???????? }
?????? else if(number<a[min])
???????? bott=min-1;
?????? else
???????? top=min+1;
?????? }
???? if(loca==0||loca==-1)
?????? printf("%d not in table\n",number);
???? printf("continue Y/N or y/n\n");
???? c=getchar();
???? if(c=='N'||c=='n')flag=0;
??? }
}

6.10
main()
{int i,j,uppn,lown,dign,span,othn;
?char text[3][80];
?uppn=lown=dign=span=othn=0;
?for(i=0;i<3;i++)
?? {gets(text[i]);
??? for(j=0;j<80&&text[i][j]!='\0';j++)
????? {if(text[i][j]>='A'&&text[i][j]<='Z')
???????? uppn++;
?????? else if(text[i][j]>='a'&&text[i][j]<='z')
???????? lown++;
?????? else if(text[i][j]>='0'&&text[i][j]<='9')
???????? dign++;
?????? else if(text[i][j]==' ')
???????? span++;
?????? else
???????? othn++;
?????? }
??? }
?for(i=0;i<3;i++)
?? printf("%s\n",text[i]);
?printf("uppn=%d\n",uppn);
?printf("lown=%d\n",lown);
?printf("dign=%d\n",dign);
?printf("span=%d\n",span);
?printf("othn=%d\n",othn);
}

6.11
main()
{static char a[5]={'*','*','*','*','*'};
?int i,j,k;
?char space=' ';
?for(i=0;i<=5;i++)
?? {printf("\n");
??? for(j=1;j<=3*i;j++)
????? printf("%1c",space);
??? for(k=0;k<=5;k++)
????? printf("%3c",a[k]);
??? }
}

6.12
#include<stdio.h>
main()
{int i,n;
?char ch[80],tran[80];
?gets(ch);
?i=0;
?while(ch[i]!='\0')
?? {if((ch[i]>='A')&&(ch[i]<='Z'))
????? tran[i]=26+64-ch[i]+1+64;
??? else if((ch[i]>='a')&&(ch[i]<='z'))
????? tran[i]=26+96-ch[i]+1+96;
??? else
????? tran[i]=ch[i];
??? i++;
??? }
?n=i;
?for(i=0;i<n;i++)
?? putchar(tran[i]);
}

6.13
main()
{char s1[80],s2[40];
?int i=0,j=0;
?scanf("%s",s1);
?scanf("%s",s2);
?while(s1[i]!='\0')i++;
?while(s2[j]!='\0')s1[i++]=s2[j++];
?s1[i]='\0';
?printf("s=%s\n",s1);
}

6.14
#include<stdio.h>
main()
{int i,resu;
?char s1[100],s2[100];
?gets(s1);
?gets(s2);
?i=0;
?while((s1[i]==s2[i])&&(s1[i]!='\0'))i++;
?if(s1[i]=='\0'&&s2[i]=='\0')resu=0;
?else
?? resu=s1[i]-s2[i];
?printf("s1=%s,s2=%s,resu=%d\n",s1,s2,resu);
}

6.15
#include"stdio.h"
main()
{char from[80],to[80];;
?int i;
?scanf("%s",from);
?for(i=0;i<=strlen(from);i++)
?? to[i]=from[i];
?printf("%s\n",to);
}

第七章
7.1
hcf(u,v)
int u,v;
{int a,b,t,r;
?if(u>v){t=u;u=v;v=t;}
?a=u;b=v;
?while((r=b%a)!=0)
?? {b=a;a=r;}
?return(a);
}
lcd(u,v,h)
int u,v,h;
{return(u*v/h);}
main()
{int u,v,h,l;
?scanf("%d,%d",&u,&v);
?h=hcf(u,v);
?printf("H.C.F=%d\n",h);
?l=lcd(u,v,h);
?printf("L.C.D=%d\n",l);
}

7.2
#include"math.h"
float x1,x2,disc,p,q;
greater_than_zero(a,b)
float a,b;
{x1=(-b+sqrt(disc))/(2*a);
?x2=(-b-sqrt(disc))/(2*a);
}
equal_to_zero(a,b)
flaot a,b;
{x1=x2=-b/(2*a);}
smaller_than_zero(a,b)
float a,b;
{p=-b/(2*a);
?q=sqrt(-disc)/(2*a);
}
main()
{float a,b,c;
?scanf("%f,%f,%f",&a,&b,&c);
?disc=b*b-4*a*c;
?if(fabs(disc)<=1e-5)
?? {equal_to_zero(a,b);
??? printf("x1=%5.2f\tx2=%5.2f\n",x1,x2);
?? }
?else if(disc>0)
?? {greater_than_zero(a,b);
??? printf("x1=%5.2f\tx2=%5.2f\n",x1,x2);
?? }
?else
?? {smaller_than_zero(a,b);
??? printf("x1=%5.2f+%5.2fi\tx2=%5.2f-%5.2fi\n",p,q,p,q);
?? }
}

7.3
main()
{int number;
?scanf("%d",&number);
?if(prime(number))
?? printf("yes");
?else
?? printf("no");
}
int prime(number)
int number;
{int flag=1,n;
?for(n=2;n<number/2&&flag==1;n++)
?? if(number%n==0)
???? flag=0;
?return(flag);
}

7.4
#define N 3
int array[N][N];
convert(array)
int array[3][3];
{int i,j,t;
?for(i=0;i<N;i++)
?? for(j=i+1;j<N;j++)
???? {t=array[i][j];
????? array[i][j]=array[j][i];
????? array[j][i]=t;
????? }
}
main()
{int i,j;
?for(i=0;i<N;i++)
?for(j=0;j<N;j++)
?? scanf("%d",&array[i][j]);
?convert(array);
?for(i=0;i<N;i++)
?? {printf("\n");
??? for(j=0;j<N;j++)
????? printf("%5d",array[i][j]);
??? }
}

7.5
main()
{char str[100];
?scanf("%s",str);
?inverse(str);
?printf("%s\n",str);
}
inverse(str)
char str[];
{char t;
?int i,j;
?for(i=0,j=strlen(str);i<strlen(str)/2;i++,j--)
?? {t=str[i];
??? str[i]=str[j-1];
??? str[j-1]=t;
??? }
}

7.6
char concate(str1,str2,str)
char str1[],str2[],str[];
{int i,j;
?for(i=0;str1[i]!='\0';i++)
?? str[i]=str1[i];
?for(j=0;str2[j]!='\0';j++)
?? str[i+j]=str2[j];
?str[i+j]='\0';
}
main()
{char s1[100],s2[100],s[100];
?scanf("%s",s1);
?scanf("%s",s2);
?concate(s1,s2,s);
?printf("\ns=%s",s);
}

7.7
main()
{char str[80],c[80];
?void cpy();
?gets(str);
?cpy(str,c);
?printf("\n%s\n",c);
}
void cpy(s,c)
char s[],c[];
{int i,j;
?for(i=0,j=0;s[i]!='\0';i++)
?? if(s[i]=='a'||s[i]=='A'||s[i]=='e'||s[i]=='E'||s[i]=='i'||
????? s[i]=='I'||s[i]=='o'||s[i]=='O'||s[i]=='u'||s[i]=='U')
???? {c[j]=s[i];j++;}
?c[j]='\0';
}

7.8
main()
{char str[80];
?scanf("%s",str);
?insert(str);
}
insert(str)
char str[];
{int i;
?for(i=strlen(str);i>0;i--)
?? {str[i*2]=str[i];
??? str[i*2-1]=' ';
?? }
?printf("%s\n",str);
}

7.9
int alph,digit,space,others;
main()
{char text[80];
?gets(text);
?alph=0,digit=0,space=0,others=0;
?count(text);
?printf("\nalph=%d,digit=%d,space=%d,others=%d\n",alph,digit,space,others);
}
count(str)
char str[];
{int i;
?for(i=0;str[i]!='\0';i++)
?? if((str[i]>='a'&&str[i]<='z')||(str[i]>='A'&&str[i]<='Z'))
???? alph++;
?? else if(str[i]>='0'&&str[i]<='9')
???? digit++;
?? else if(strcmp(str[i],' ')==0)
???? space++;
?? else
???? others++;
}

7.10
int alph(c)
char c;
{if((c>='a'&&c<='z')||(c>='A'&&c<='Z'))
?? return(1);
?else
?? return(0);
}
int longest(string)
char string[];
{int len=0,i,length=0,flag=1,place,point;
?for(i=0;i<=strlen(string);i++)
?? if(alph(string[i]))
???? if(flag)
?????? {point=i;
??????? flag=0;
?????? }
???? else
?????? len++;
??? else
????? {flag=1;
?????? if(len>length)
???????? {length=len;
????????? place=point;
????????? len=0;
????????? }
?????? }
?return(place);
}
main()
{int i;
?char line[100];
?gets(line);
?for(i=longest(line);alph(line[i]);i++)
?? printf("%c",line[i]);
?printf("\n");
}

7.11
#define N 10
char str[N];
main()
{int i,flag;
?for(flag=1;flag==1;)
?? {scanf("%s",str);
??? if(strlen(str)>N)
????? printf("input error");
??? else
????? flag=0;
??? }
?sort(str);
?for(i=0;i<N;i++)
?? printf("%c",str[i]);
}
sort(str)
char str[N];
{int i,j;
?char t;
?for(j=1;j<N;j++)
?? for(i=0;(i<N-j)&&(str[i]!='\0');i++)
???? if(str[i]>str[i+1])
?????? {t=str[i];
??????? str[i]=str[i+1];
??????? str[i+1]=t;
?????? }
}

7.12
#include<math.h>
float solut(a,b,c,d)
float a,b,c,d;
{float x=1,x0,f,f1;
?do
?? {x0=x;
??? f=((a*x0+b)*x0+c)*x0+d;
??? f1=(3*a*x0+2*b)*x0+c;
??? x=x0-f/f1;
??? }
?while(fabs(x-x0)>=1e-5);
?return(x);
}
main()
{float a,b,c,d;
?scanf("%f,%f,%f,%f",&a,&b,&c,&d);
?printf("x=%10.7f\n",solut(a,b,c,d));
}

7.13
main()
{int x,n;
?float p();
?scanf("%d,%d",&n,&x);
?printf("P%d(%d)=%10.2f\n",n,x,p(n,x));
}
float p(tn,tx)
int tn,tx;
{if(tn==0)
?? return(1);
?else if(tn==1)
?? return(tx);
?else
?? return(((2*tn-1)*tx*p((tn-1),tx)-(tn-1)*p((tn-2),tx))/tn);
}

7.14
#define N 10
#define M 5
float score[N][M];
float a_stu[N],a_cor[M];
main()
{int i,j,r,c;
?float h;
?float s_diff();
?float highest();
?r=0;
?c=1;
?input_stu();
?avr_stu();
?avr_cor();
?printf("\n? number? class? 1? 2? 3? 4? 5? avr");
?for(i=0;i<N;i++)
?? {printf("\nNO%2d",i+1);
??? for(j=0;j<M;j++)
????? printf("%8.2f",score[i][j]);
??? printf("%8.2f",a_stu[i]);
??? }
?printf("\nclassavr");
?for(j=0;j<M;j++)
?? printf("%8.2f",a_cor[j]);
?h=highest(&r,&c);
?printf("\n\n%8.2f??? %d??? %d\n",h,r,c);
?printf("\n?? %8.2f\n",s_diff());
}
input_stu()
{int i,j;
?float x;
?for(i=0;i<N;i++)
?? {for(j=0;j<M;j++)
????? {scanf("%f",&x);
?????? score[i][j]=x;
????? }
??? }
}
avr_stu()
{int i,j;
?float s;
?for(i=0;i<N;i++)
?? {for(j=0,s=0;j<M;j++)
????? s+=score[i][j];
??? a_stu[i]=s/5.0;
?? }
}
avr_cor()
{int i,j;
?float s;
?for(j=0;j<M;j++)
?? {for(i=0,s=0;i<N;i++)
????? s+=score[i][j];
??? a_cor[j]=s/(float)N;
?? }
}
float highest(r,c)
int *r,*c;
{float high;
?int i,j;
?high=score[0][0];
?for(i=0;i<N;i++)
?? for(j=0;j<M;j++)
???? if(score[i][j]>high)
?????? {high=score[i][j];
??????? *r=i+1;
??????? *c=j+1;
??????? }
?return(high);
}
float s_diff()
{int i,j;
?float sumx=0.0,sumxn=0.0;
?for(i=0;i<N;i++)
?? {sumx+=a_stu[i]*a_stu[i];
??? sumxn+=a_stu[i];
?? }
?return(sumx/N-(sumxn/N)*(sumxn/N));
}

7.15
#include<stdio.h>
#define N 10
void input_e(num,name)
int num[];
char name[N][8];
{int i;
?for(i=0;i<N;i++)
?? {scanf("%d",&num[i]);
??? gets(name[i]);
?? }
}
void sort(num,name)
int num[];
char name[N][8];
{int i,j,min,temp1;
?char temp2[8];
?for(i=0;i<N-1;i++)
?? {min=i;
??? for(j=i;j<N;j++)
????? if(num[min]>num[j])min=j;
??? temp1=num[i];
??? num[i]=num[min];
??? num[min]=temp1;
??? strcpy(temp2,name[i]);
??? strcpy(name[i],name[min]);
??? strcpy(name[min],temp2);
?? }
?for(i=0;i<N;i++)
?? printf("\n%5d%10s",num[i],name[i]);
}
void search(n,num,name)
int n,num[];
char name[N][8];
{int top,bott,min,loca;
?loca=0;
?top=0;
?bott=N-1;
?if((n<num[0])||(n>num[N-1]))
?? loca=-1;
?while((loca==0)&&(top<=bott))
?? {min=(bott+top)/2;
??? if(n==num[min])
????? {loca=min;
?????? printf("number=%d,name=%s\n",n,name[loca]);
????? }
??? else if(n<num[min])
????? bott=min-1;
??? else
????? top=min+1;
??? }
?if(loca==0||loca==-1)
?? printf("number=%d is not in table\n",n);
}
main()
{int num[N],number,flag,c,n;
?char name[N][8];
?input_e(num,name);
?sort(num,name);
?for(flag=1;flag;)
?? {scanf("%d",&number);
??? search(number,num,name);
??? printf("continue?Y/N!");
??? c=getchar();
??? if(c=='N'||c=='n')
????? flag=0;
?? }
}

7.16
#include<stdio.h>
#define MAX 1000
main()
{int c,i,flag,flag1;
?char t[MAX];
?i=0;
?flag=0;
?flag1=1;
?while((c=getchar())!='\0'&&i<MAX&&flag1)
?? {if(c>='0'&&c<='9'||c>='A'&&c<='F'||c>='a'&&c<='f')
????? {flag=1;
?????? t[i++]=c;
????? }
??? else if(flag)
????? {t[i]='\0';
?????? printf("\nnumber=%d\n",htoi(t));
?????? printf("continue?");
?????? c=getchar();
?????? if(c=='n'||c=='N')
???????? flag1=0;
?????? else
???????? {flag=0;
????????? i=0;
????????? }
?????? }
???? }
}
htoi(s)
char s[];
{int i,n;
?n=0;
?for(i=0;s[i]!='\0';i++)
?? {if(s[i]>='0'&&s[i]<='9')
????? n=n*16+s[i]-'0';
??? if(s[i]>='a'&&s[i]<='f')
????? n=n*16+s[i]-'a'+10;
??? if(s[i]>='A'&&s[i]<='F')
????? n=n*16+s[i]-'A'+10;
??? }
?return(n);
}

7.17
#include<stdio.h>
void convert(n)
int n;
{int i;
?if((i=n/10)!=0)
?? convert(i);
?putchar(n%10+'0');
}
main()
{int number;
?scanf("%d",&number);
?if(number<0)
?? {putchar('-');
??? number=-number;
?? }
?convert(number);
}

7.18
main()
{int year,month,day;
?int days;
?scanf("\n%d,%d,%d",&year,&month,&day);
?days=sum_day(month,day);
?if(leap(year)&&(month>=3))
?? days+=1;
?printf("days=%d\n",days);
}
static int day_tab[13]={0,31,28,31,30,31,30,31,31,30,31,30,31}
int sum_day(month,day)
int month,day;
{int i;
?for(i=1;i<month;i++)
?? day+=day_tab[i];
?return(day);
}
int leap(year)
int year;
{int leap;
?leap=year%4==0&&year%100!=0||year%400==0;
?return(leap);
}

第八章? 編譯預處理
8.1
#define SWAP(a,b) t=b;b=a;a=t
main()
{int a,b,t;
?scanf("%d,%d",&a,&b);
?SWAP(a,b);
?printf("a=%d\tb=%d\n",a,b);
}

8.2
#define SURPLUS(a,b) ((a)%(b))
main()
{int a,b;
?scanf("%d,%d",&a,&b);
?printf("%d",SURPLUS(a,b));
}

8.3
#include"math.h"
#define S(a,b,c) ((a+b+c)/2)
#define AREA(a,b,c) (sqrt(S(a,b,c)*(S(a,b,c)-a)*(S(a,b,c)-b)*(S(a,b,c)-c)))
main()
{float a,b,c;
?scanf("%f,%f,%f",&a,&b,&c);
?if(a+b>c&&b+c>a&&a+c>b)
?? printf("area=%8.2f\n",AREA(a,b,c));
?else
?? printf("input error");
}

8.4
#define LEAP(y) (y%4==0)&&(y%100!=0)||(y%400==0)
main()
{int year;
?scanf("%d",&year);
?if(LEAP(year))
?? printf("yes");
?else
?? printf("no");
}

8.5
printf("value=%format\t",x);
printf("value=%format\t",x);putchar('\n');
printf("value=%format\t",x1);printf("value=%format\t",x2);putchar('\n');
輸出結果：
value=5.000000ormat??????? value=5.000000ormat
value=3.000000ormat??????? value=8.000000ormat

8.6
#define PR printf
#define NL "\n"
#define Fs "%f"
#define F "%6.2f"
#define F1 F NL
#define F2 F "\t" F NL
#define F3 F "\t" F "\t" F NL
main()
{float a,b,c;
?scanf(Fs,&a);
?scanf(Fs,&b);
?scanf(Fs,&c);
?PR(NL);
?PR(F1,a);
?PR(F1,b);
?PR(F1,c);
?PR(NL);
?PR(F2,a,b);
?PR(F1,c);
?PR(NL);
?PR(F3,a,b,c);
}

8.7
/*format.h文件*/
#define DIGIT(d) printf("%d\n",d)
#define FLOAT(f) printf("%8.2f\n",f)
#define STRING(s) printf("%s\n",s)
/*用戶文件*/
#include"format.h"
main()
{int d,num;
?float f;
?char s[80];
?scanf("%d",&num);
?switch(num)
?? {case 1:scanf("%d",&d);
?????????? DIGIT(d);
?????????? break;
??? case 2:scanf("%f",&f);
?????????? FLOAT(f);
?????????? break;
??? case 3:scanf("%s",s);
?????????? STRING(s);
?????????? break;
??? default:printf("error");
?? }
}

8.8
main()
{int a,b,c;
?scanf("%d,%d,%d",&a,&b,&c);
?printf("max=%d\n",max(a,b,c));
}
max(a,b,c)
int a,b,c;
{int t;
?t=x>y?x:y;
?return(t>z?t:z);
}

#define MAX(a,b) ((a)>(b)?(a):(b))
main()
{int a,b,c;
?scanf("%d,%d,%d",&a,&b,&c);
?printf("max=%d\n",MAX(MAX(a,b),c));
}

8.10
#include"stdio.h"
#define MAX 80
#define CHANGE 1
main()
{char str[MAX];
?int i;
?scanf("%s",str);
?#if(CHANGE)
?? {for(i=0;i<MAX;i++)
????? {if(str[i]!='\0')
???????? if(str[i]>='a'&&str[i]<'z'||str[i]>='A'&&str[i]<'Z')
?????????? str[i]++;
???????? else if(str[i]=='z'||str[i]=='Z')
?????????? str[i]-=25;
????? }
??? }
?#endif
?printf("\n%s\n",str);
}

第九章? 指針
9.1
main()
{int n1,n2,n3;
?int *p1,*p2,*p3;
?scanf("%d,%d,%d",&n1,&n2,&n3);
?p1=&n1;
?p2=&n2;
?p3=&n3;
?if(n1>n2)swap(p1,p2);
?if(n1>n3)swap(p1,p3);
?if(n2>n3)swap(p2,p3);
?printf("%d,%d,%d\n",n1,n2,n3);
}
swap(p1,p2)
int *p1,*p2;
{int p;
?p=*p1;*p1=*p2;*p2=p;
}

9.2
main()
{char *str1[20],*str2[20],*str3[20];
?char swap();
?scanf("%s",str1);
?scanf("%s",str2);
?scanf("%s",str3);
?if(strcmp(str1,str2)>0)swap(str1,str2);
?if(strcmp(str1,str3)>0)swap(str1,str3);
?if(strcmp(str2,str3)>0)swap(str2,str3);
?printf("%s\n%s\n%s\n",str1,str2,str3);
}
char swap(p1,p2)
char *p1,*p2;
{char *p[20];
?strcpy(p,p1);
?strcpy(p1,p2);
?strcpy(p2,p);
}

9.3
main()
{int number[10];
?input(number);
?max_min_value(number);
?output(number);
?}
input(number)
int number[10];
{int i;
?for(i=0;i<10;i++)
?? scanf("%d",&number[i]);
}
max_min_value(number)
int number[10];
{int *max,*min;
?int *p,*end;
?end=number+10;
?max=min=number;
?for(p=number+1;p<end;p++)
?? if(*p>*max)max=p;
?? else if(*p<*min)min=p;
?*p=number[0];
?number[0]=*min;
?*min=*p;
?*p=number[9];
?number[9]=*max;
?*max=*p;
?return;
}
output(number)
int number[10];
{int *p;
?for(p=number;p<number+9;p++)
?? printf("%d,",*p);
?printf("%d\n",*p);
}

9.4
main()
{int number[20],n,m,i;
?scanf("%d",&n);
?scanf("%d",&m);
?for(i=0;i<n:i++)
?? scanf("%d",&number[i]);
?move(number,n,m);
?for(i=0;i<n;i++)
?? printf("%8d",number[i]);
}
move(array,n,m)
int array[20],n,m;
{int *p,end;
?end=*(array+n-1);
?for(p=array+n-1;p>array;p--)
?? *p=*(p-1);
?*array=end;
?m--;
?if(m>0)move(array,n,m);
}

9.5
#define nmax 50
main()
{int i,k,m,n,num[nmax],*p;
?scanf("%d",&n);
?p=num;
?for(i=0;i<n;i++)
?? *(p+i)=i+1;
?i=k=m=0;
?while(m<n-1)
?? {if(*(p+i)!=0)k++;
??? if(k==3)
????? {*(p+i)=0;
?????? k=0;
?????? m++;
????? }
??? i++;
??? if(i==n)i=0;
??? }
?while(*p==0)p++;
?printf("%d",*p);
}

9.6
main()
{int len;
?char *str[20];
?scanf("%s",str);
?len=length(str);
?printf("\nlen=%d\n",len);
}
length(p)
char *p;
{int n=0;
?while(*p!='\0')
?? {n++;p++;}
?return(n);
}

9.7
main()
{int m;
?char *str1[20],*str2[20];
?scanf("%s",str1);
?scanf("%d",&m);
?if(strlen(str1)<m)
?? printf("error");
?else
?? {copystr(str1,str2,m);
??? printf("%s",str2);
?? }
}
copystr(p1,p2,m)
char *p1,*p2;
int m;
{int n=0;
?while(n<m-1)
?? {n++;p1++;}
?while(*p1!='\0')
?? {*p2=*p1;
??? p1++;
??? p2++;
?? }
?*p2='\0';
}

9.8
#include"stdio.h"
main()
{int cle=0,sle=0,di=0,wsp=0,ot=0,i;
?char *p,s[20];
?for(i=0;i<20;i++)s[i]=0;
?i=0;
?while((s[i]=getchar())!='\n')i++;
?p=s;
?while(*p!='\n')
?? {if(*p>='a'&&*p<='z')
????? ++sle;
??? else if(*p>='A'&&*p<='Z')
????? ++cle;
??? else if(*p==' ')
????? ++wsp;
??? else if(*p>='0'&&*p<='9')
????? ++di;
??? else
????? ++ot;
??? p++;
?? }
?printf("sle=%d,cle=%d,wsp=%d,di=%d,ot=%d\n",sle,cle,wsp,di,ot);
}

9.9
main()
{int a[3][3],*p,i;
?for(i=0;i<3;i++)
?? scanf("%d,%d,%d",a[i][0],a[i][1],a[i][2]);
?p=a;
?move(p);
?for(i=0;i<3;i++)
?? printf("%d? %d? %d\n",a[i][0],a[i][1],a[i][2]);
}
move(pointer)
int *pointer;
{int i,j,t;
?for(i=0;i<2;i++)
?for(j=i+1;j<3;j++)
?? {t=*(pointer+3*i+j);
??? *(pointer+3*i+j)=*(pointer+3*j+i);
??? *(pointer+3*j+i)=t;
?? }
}

9.10
main()
{int a[5][5],*p,i,j;
?for(i=0;i<5;i++)
?for(j=0;j<5;j++)
?? scanf("%d",&a[i][j]);
?p=a;
?change(p);
?for(i=0;i<5;i++)
?? {printf("\n");
??? for(j=0;j<5;j++)
????? printf("%8d",a[i][j]);
??? }
}
change(p)
int *p;
{int i,j,change;
?int *pmax,*pmin;
?pmax=p;
?pmin=p;
?for(i=0;i<5;i++)
?? for(j=0;j<5;j++)
???? {if(*pmax<*(p+5*i+j))pmax=p+5*i+j;
????? if(*pmin>*(p+5*i+j))pmin=p+5*i+j;
???? }
?change=*(p+12);
?*(p+12)=*pmax;
?*pmax=change;
?change=*p;
?*p=*pmin;
?*pmin=change;
?pmin=p+1;
?for(i=0;i<5;i++)
?? for(j=0;j<5;j++)
???? if(((p+5*i+j)!=p)&&(*pmin>*(p+5*i+j)))pmin=p+5*i+j;
?change=*(p+4);
?*(p+4)=*pmin;
?*pmin=change;
?pmin=p+1;
?for(i=0;i<5;i++)
?? for(j=0;j<5;j++)
???? if(((p+5*i+j)!=(p+4))&&((p+5*i+j)!=p)&&(*pmin>*(p+5*i+j)))
??????? pmin=p+5*i+j;
?change=*(p+20);
?*(p+20)=*pmin;
?*pmin=change;
?pmin=p+1;
?for(i=0;i<5;i++)
?? for(j=0;j<5;j++)
???? if(((p+5*i+j)!=p)&&((p+5*i+j)!=(p+4))&&((p+5*i+j)!=(p+20))
??????????? &&(*pmin>*(p+5*i+j)))pmin=p+5*i+j;
?change=*(p+24);
?*(p+24)=*pmin;
?*pmin=change;
}

9.11
main()
{int i;
?char *p,str[10][10];
?for(i=0;i<10;i++)
?? scanf("%s",str[i]);
?p=str;
?sort(p);
?for(i=0;i<10;i++)
?? printf("%s\n",str[i]);
}
sort(p)
char *p;
{int i,j;
?char s[10],*smax,*smin;
?for(i=0;i<10;i++)
?? {smax=p+10*i;
??? for(j=i+1;j<10;j++)
????? {smin=p+10*j;
?????? if(strcmp(smax,smin)>0)
???????? {strcpy(s,smin);
????????? strcpy(smin,smax);
????????? strcpy(smax,s);
???????? }
?????? }
??? }
}

9.12
#define MAX 20
main()
{int i;
?char *pstr[10],str[10][MAX];
?for(i=0;i<10;i++)
?? pstr[i]=str[i];
?for(i=0;i<10;i++)
?? scanf("%s",pstr[i]);
?sort(pstr);
?for(i=0;i<10;i++)
?? printf("%s\n",pstr[i]);
}
sort(pstr)
char *pstr[10];
{int i,j;
?char *p;
?for(i=0;i<10;i++)
?? {for(j=i+1;j<10;j++)
????? {if(strcmp(*(pstr+i),*(pstr+j))>0)
???????? {p=*(pstr+i);
????????? *(pstr+i)=*(pstr+j);
????????? *(pstr+j)=p;
????????? }
?????? }
??? }
}

9.13
#include"math.h"
main()
{int n=20;
?float a,b,a1,b1,a2,b2,c,(*p)(),jiff();
?scanf("%f,%f",&a,&b);
?scanf("%f,%f",&a1,&b1);
?scanf("%f,%f",&a2,&b2);
?p=sin;
?c=jiff(a,b,n,p);
?printf("sin=%f\n",c);
?p=cos;
?c=jiff(a1,b1,n,p);
?printf("cos=%f\n",c);
?p=exp;
?c=jiff(a2,b2,n,p);
?printf("exp=%f\n",c);
}
float jiff(a,b,n,p)
float a,b,(*p)();
int n;
{int i;
?float x,f,h,area;
?h=(b-a)/n;
?x=a;
?area=0;
?for(i=1;i<=n;i++)
?? {x=x+h;
??? area=area+(*p)(x)*h;
??? }
?return(area);
}

9.14
main()
{int i,n,num[20];
?char *p;
?scanf("%d",&n);
?for(i=0;i<n;i++)
?? scanf("%d",&num[i]);
?p=num;
?sort(p,n);
?for(i=0;i<n;i++)
?? printf("%8d",num[i]);
}
sort(p,m)
char *p;
int m;
{int i;
?char change,*p1,*p2;
?for(i=0;i<m/2;i++)
?? {p1=p+i;
??? p2=p+(m-1-i);
??? change=*p1;
??? *p1=*p2;
??? *p2=change;
??? }
}

9.15
main()
{int i,j,*pnum,num[4];
?float score[4][5],aver[4],*psco,*pave;
?char course[5][10],*pcou;
?pcou=course[0];
?for(i=0;i<5;i++)
?? scanf("%s",pcou+10*i);
?printf("number");
?for(i=0;i<5;i++)
?? printf(",%s",pcou+10*i);
?printf("\n");
?psco=score;
?pnum=num;
?for(i=0;i<4;i++)
?? {scanf("%d",pnum+i);
??? for(j=0;j<5;j++)
????? scanf(",%f",psco+5*i+j);
?? }
?pave=aver;
?printf("\n");
?avsco(psco,pave);
?avcour1(pcou,psco);
?printf("\n");
?fali2(pcou,pnum,psco,pave);
?printf("\n");
?good(pcou,pnum,psco,pave);
}
avsco(psco,pave)
float *psco,*pave;
{int i,j;
?float sum,average;
?for(i=0;i<4;i++)
?? {sum=0;
??? for(j=0;j<5;j+)
????? sum+=(*(psco+5*i+j));
??? average=sum/5;
??? *(pave+i)=average;
?? }
}
avcour1(pcou,psco)
char *pcou;
float *psco;
{int i;
?float sum,average1;
?sum=0;
?for(i=0;i<4;i++)
?? sum+=(*(psco+5*i))
?average1=sum/4;
?printf("%s????? %5.2f\n",pcou,average1);
}
fali2(pcou,pnum,psco,pave)
char *pcou;
int *pnum;
float *psco,*pave;
{int i,j,k,label;
?printf("\nnumber\n");
?for(i=0;i<5;i++)
?? printf("%-8s",pcou+10*i);
?printf("\naverage\n");
?for(i=0;i<4;i++)
?? {label=0;
??? for(j=0;j<5;j++)
????? if(*(psco+5*i+j)<60.0)label++;
??? if(label>=2)
????? {printf("%-8d",*(pnum+i));
?????? for(k=0;k<5;k++)
???????? printf("%-8.2f",*(psco+5*i+k));
?????? printf("%-8.2f",*(pave+i));
????? }
??? }
}
good(pcou,pnum,psco,pave)
char *pcou;
int *pnum;
float *psco,*pave;
{int i,j,k,label;
?printf("number");
?for(i=0;i<5;i++)
?? printf("%-8s",pcou+10*i);
?printf("average");
?for(i=0;i<4;i++)
?? {label=0;
??? for(j=0;j<5;j++)
????? if(*(psco+5*i+j)>=85.0)label++;
??? if((label>=5)||(*(pave+i)>=90))
????? {printf("%-8d",*(pnum+i));
?????? for(k=0;k<5;k++)
???????? printf("%-8.2f",*(psco+5*i+k));
?????? printf("%-8.2f",*(pave+i));
????? }
??? }
}

9.16
#include"stdio.h"
main()
{char str[50],*pstr;
?int i,j,k,m,e10,digit,ndigit,a[10],*pa;
?gets(str);
?pstr=str;
?pa=a;
?ndigit=0;
?i=j=0;
?while(*(pstr+i)!='\0')
?? {if((*(pstr+i)>='0')&&(*(pstr+i)<='9'))
????? j++;
??? else
????? {if(j>0)
???????? {digit=*(pstr+i-1)-48;
????????? k=1;
????????? while(k<j)
??????????? {e10=1;
???????????? for(m=1;m<=k;m++)
?????????????? e10=e10*10;
???????????? digit+=(*(pstr+i-1-k)-48)*e10;
???????????? k++;
??????????? }
?????????? *pa=digit;
?????????? ndigit++;
?????????? pa++;
?????????? j=0;
????????? }
??????? }
???? i++;
???? }
?if(j>0)
?? {digit=*(pstr+i-1)-48;
??? k=1;
??? while(k<j)
????? {e10=1;
?????? for(m=1;m<=k;m++)
????????? e10=e10*10;
?????? digit+=(*(pstr+i-1-k)-48)*e10;
?????? k++;
?????? }
???? *pa=digit;
???? ndigit++;
???? j=0;
??? }???
?printf("ndigit=%d\n",ndigit);
?j=0;
?pa=a;
?for(j=0;j<ndigit;j++)
?? printf("%d",*(pa+j));
}

9.17
main()
{int m;
?char str1[20],str2[20],*p1,*p2;
?scanf("%s",str1);
?scanf("%s",str2);
?p1=str1;
?p2=str2;
?m=strcmp(p1,p2);
?printf("%d\n",m);
}
strcmp(p1,p2)
char *p1,*p2;
{int i=0;
?while(*(p1+i)==*(p2+i))
?? if(*(p+i++)=='\0')return(0);
?return(*(p1+i)-*(p2+i));
}

9.18
main()
{static char *mname[13]={"illeagl","January","February","March",
?? "April","May","June","July","August","September","October",
?? "November","December"};
?int n;
?scanf("%d",&n);
?if((n>=1)&&(n<=12))
?? printf("%s\n",*(mname+n));
?else
?? printf("error");
}

9.20
main()
{int i;
?char **p,*pstr[5],str[5][10];
?for(i=0;i<5;i++)
?? pstr[i]=str[i];
?for(i=0;i<5;i++)
?? scanf("%s",pstr[i]);
?p=pstr;
?sort(p);
?for(i=0;i<5;i++)
?? printf("%s\n",pstr[i]);
}
sort(p)
char **P;
{int i,j;
?char *pchange;
?for(i=0;i<5;i++)
?? {for(j=i+1;j<5;j++)
????? {if(strcmp(*(p+i),*(p+j))>0)
???????? {pchange=*(p+i);
????????? *(p+i)=*(p+j);
????????? *(p+j)=pchange;
???????? }
?????? }
??? }
}

9.21
main()
{int i,n,digit[20],**p,*pstr[20];
?scanf("%d",&n);
?for(i=0;i<n;i++)
?? pstr[i]=&digit[i];
?for(i=0;i<n;i++)
?? scanf("%d",pstr[i]);
?p=pstr;
?sort(p,n);
?for(i=0;i<n;i++)
?? printf("%d?? ",*pstr[i]);
}
sort(p,n)
int **p,n;
{int i,j,*pchange;
?for(i=0;i<n;i++)
?? {for(j=i+1;j<n;j++)
????? {if(**(p+i)>**(p+j))
???????? {pchange=*(p+i);
????????? *(p+i)=*(p+j);
????????? *(p+j)=pchange;
???????? }
????? }
??? }
}

第十章? 結構體與共用體
10.1
struct
? {int year;
?? int month;
?? int day;
? }date;
main()
{int days;
?scanf("%d,%d,%d",&date.year,&date.month,&date.day);
?switch(date.month)
?? {case 1:days=date.day;break;
??? case 2:days=date.day+31;break;
??? case 3:days=date.day+59;break;
??? case 4:days=date.day+90;break;
??? case 5:days=date.day+120;break;
??? case 6:days=date.day+151;break;
??? case 7:days=date.day+181;break;
??? case 8:days=date.day+212;break;
??? case 9:days=date.day+243;break;
??? case 10:days=date.day+273;break;
??? case 11:days=date.day+304;break;
??? case 12:days=date.day+334;break;
??? }
?if((date.year%4==0&&date.year%100!=0||date.year%400==0)
????????????????????????? &&date.month>=3)
?? days+=1;
?printf("days=%d\n",days);
}

10.2
struct dt
? {int year;
?? int month;
?? int day;
? }date;
main()
{
?scanf("%d,%d,%d",&date.year,&date.month,&date.day);
?printf("\n%d\n",days(date.year,date.month,date.day));
}
days(year,month,day)
int year,month,day;
{int daysum=0,i;
?static int daytab[13]={0,31,28,31,30,31,30,31,31,30,31,30,31}
?for(i=1;i<month;i++)
?? daysum+=daytab[i];
?daysum+=day;
?if((year%4==0&&year%100!=0||year%400==0)&&month>=3)
?? daysum+=1;
?return(daysum);
}

10.3
10.4
#define N 5
struct student
? {char num[6];
?? char name[8];
?? int score[4];
?? }stu[N];
main()
{
?input(stu);
?print(stu);
}
input(stu)
struct student stu[];
{int i,j;
?for(i=0;i<N;i++)
?? {printf("number");
??? scanf("%s",stu[i].num);
??? printf("name");
??? scanf("%s",stu[i].name);
??? for(j=0;j<3;j++)
????? {printf("\nscore\n");
?????? scanf("%d",&stu[i].score[j]);
????? }
??? printf("\n");
??? }
}
print(stu)
struct student stu[];
{int i,j;
?printf("\nnumber?? name? score1? score2? score3? \n");
?for(i=0;i<N;i++)
?? {printf("%8s%10s",stu[i].num,stu[i].name);
??? for(j=0;j<3;j++)
????? printf("%7d",stu[i].score[j]);
??? printf("\n");
?? }
}

10.5
struct student
? {char num[6];
?? char name[8];
?? int score[4];
?? float avr;
?? }stu[5];
main()
{int i,j,max,maxi,sum;
?float average;
?for(i=0;i<5;i++)
?? {printf("number");
??? scanf("%s",stu[i].num);
??? printf("name");
??? scanf("%s",stu[i].name);
??? for(j=0;j<3;j++)
????? {printf("\nscore\n");
?????? scanf("%d",&stu[i].score[j]);
????? }
??? }
?average=0;
?max=0;
?maxi=0;
?for(i=0;i<5;i++)
?? {sum=0;
??? for(j=0;j<3;j++)
????? sum+=stu[i].score[j];
??? stu[i].avr=sum/3.0;
??? average+=stu[i].avr;
??? if(sum>max)
????? {max=sum;
?????? maxi=i;
????? }
??? }
?average/=5;
?printf("number?? name? score1? score2? score3? average\n");
?for(i=0;i<5;i++)
?? {printf("%8s%10s",stu[i].num,stu[i].name);
??? for(j=0;j<3;j++)
????? printf("%7d",stu[i].score[j]);
??? printf("%6.2f\n",stu[i].avr);
?? }
?printf("average=%5.2f\n",average);
?printf("The best student is %s,sum=%d\n",stu[maxi].name,max);
}