鏈鍒濈殑鎯蟲硶“鍏堥氳繃姝e父鐨勪簩鍒嗘煡鎵捐繑鍥炰竴涓綅緗畃os錛岀劧鍚庡湪浜屽垎鏌ユ壘0-pos錛屽鏋滄湁鍚堥傜殑newpos緇х畫0-newpos錛屼笉榪囨槸log2N + log2(N/2)+銆傘傘?#8221;
浼樺寲鍚?/p>
1 姝e父鐨勪簩鍒嗘煡鎵捐繑鍥炰竴涓綅緗畃os 錛屾鏃剁殑pos 鏄敱 left right 鐢熸垚 錛岃漿鍒扮浜屾
2 緇х畫璋冪敤 浜屽垎鎼滅儲 鍦?left 鍜?pos –1 涓煡鎵緆ey 錛?濡傛灉鎵懼埌 緇х畫絎簩姝ワ紝濡傛灉娌℃湁絎笁姝?/p>
3 姝ゆ椂鍙互璇存槑 left – pos –1 涓?涓嶅瓨鍦?key 錛岄偅涔堝彲浠ヨ pos 灝辨槸絎竴嬈″嚭鐜扮殑涓嬫爣
# include<stdio.h> #define DEBUG int bsearch(int array[],int &start ,int &end ,int key) { int i,j; int mid; i = start; j = end ; while(i <= j) { mid = (i+j)/2; #ifdef DEBUG // printf("now i j and mid is %d %d %d\n",i,j,mid); #endif if(array[mid] == key) return mid; else if(array[mid] < key) i = mid + 1; else j = mid - 1; } start = i,end = mid; return -1; } int FirstBsearch(int array[],int start ,int end ,int key) { int i,j; int mid,pos; i = start; j = end ; mid = bsearch(array,start ,end ,key); if(array[mid] == key)//濡傛灉鎵懼埌浜?/span> { pos = mid; while( pos != -1 ) { j = pos -1; pos = bsearch(array ,i ,j ,key); } return j+1; } return -1; } int main() { int data[11] = {1,3,4,7,7,7,7,56,134,134,132487990}; int key,i; int start = 0,end =10; for(i = 0 ; i < 4; i ++) { scanf("%d",&key); printf("%d",FirstBsearch(data,start,end,key)); } return 0; }
鎴戠嫭绔嬪崥瀹㈢殑銆鍘熸枃銆銆銆嬈㈣繋澶у璁塊棶錛屾壒璇勬寚姝o紱
#ifndef THING_H_ #define THING_H_ #include <iostream> #include <string> using namespace std; class Thing { public: Thing(int n) : m_Num(n) { } ~Thing() { cout << "destructor called: " << m_Num << endl; } private: string m_String; int m_Num; }; #endif
榪愯緇撴灉
destructor called: 107 destructor called: 106 destructor called: 101 destructor called: 104 destructor called: 103 destructor called: 102 destructor called: 101
Precedence | Operator | Description | Example | Associativity |
---|---|---|---|---|
1 | () [] -> . :: ++ -- |
Grouping operator Array access Member access from a pointer Member access from an object Scoping operator Post-increment Post-decrement |
(a + b) / 4; array[4] = 2; ptr->age = 34; obj.age = 34; Class::age = 2; for( i = 0; i < 10; i++ ) ... for( i = 10; i > 0; i-- ) ... |
left to right |
2 | ! ~ ++ -- - + * & (type) sizeof |
Logical negation Bitwise complement Pre-increment Pre-decrement Unary minus Unary plus Dereference Address of Cast to a given type Return size in bytes |
if( !done ) ... flags = ~flags; for( i = 0; i < 10; ++i ) ... for( i = 10; i > 0; --i ) ... int i = -1; int i = +1; data = *ptr; address = &obj; int i = (int) floatNum; int size = sizeof(floatNum); |
right to left |
3 | ->* .* |
Member pointer selector Member pointer selector |
ptr->*var = 24; obj.*var = 24; |
left to right |
4 | * / % |
Multiplication Division Modulus |
int i = 2 * 4; float f = 10 / 3; int rem = 4 % 3; |
left to right |
5 | + - |
Addition Subtraction |
int i = 2 + 3; int i = 5 - 1; |
left to right |
6 | << >> |
Bitwise shift left Bitwise shift right |
int flags = 33 << 1; int flags = 33 >> 1; |
left to right |
7 | < <= > >= |
Comparison less-than Comparison less-than-or-equal-to Comparison greater-than Comparison geater-than-or-equal-to |
if( i < 42 ) ... if( i <= 42 ) ... if( i > 42 ) ... if( i >= 42 ) ... |
left to right |
8 | == != |
Comparison equal-to Comparison not-equal-to |
if( i == 42 ) ... if( i != 42 ) ... |
left to right |
9 | & | Bitwise AND | flags = flags & 42; | left to right |
10 | ^ | Bitwise exclusive OR | flags = flags ^ 42; | left to right |
11 | | | Bitwise inclusive (normal) OR | flags = flags | 42; | left to right |
12 | && | Logical AND | if( conditionA && conditionB ) ... | left to right |
13 | || | Logical OR | if( conditionA || conditionB ) ... | left to right |
14 | ? : | Ternary conditional (if-then-else) | int i = (a > b) ? a : b; | right to left |
15 | = += -= *= /= %= &= ^= |= <<= >>= |
Assignment operator Increment and assign Decrement and assign Multiply and assign Divide and assign Modulo and assign Bitwise AND and assign Bitwise exclusive OR and assign Bitwise inclusive (normal) OR and assign Bitwise shift left and assign Bitwise shift right and assign |
int a = b; a += 3; b -= 4; a *= 5; a /= 2; a %= 3; flags &= new_flags; flags ^= new_flags; flags |= new_flags; flags <<= 2; flags >>= 2; |
right to left |
16 | , | Sequential evaluation operator | for( i = 0, j = 0; i < 10; i++, j++ ) ... | left to right |
10
a
ab
hello
that
those
dict
youdao
world
your
dictionary
6
bob
d
dict
dicti
yo
z
bob
dict dictionary
dict dictionary
dictionary
youdao your
z