NOI的題目，其實就是中位數(shù)的一個應用吧。地址：
http://acm.pku.edu.cn/JudgeOnline/problem?id=1723
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
typedef struct
{
int x;
int y;
}type;
type p[10001];
int cmpx ( const void *a, const void *b )
{
return ( ( type * )a )->x - ( ( type * )b )->x;
}
int cmpy ( const void *a, const void *b )
{
return ( ( type * )a )->y - ( ( type * )b )->y;
}
int main ()
{
int n;
while ( scanf ( "%d", &n ) != EOF )
{
for ( int i=0; i<n; i++ )
{
scanf ( "%d%d", &p[i].x, &p[i].y );
}
if ( n == 1 )
{
printf ( "0\n" );
continue;
}
int mid;
int ans = 0;
qsort ( p, n, sizeof ( type ), cmpy );
if ( ! n & 1 )
{
mid = ( p[n/2].y + p[n/2-1].y ) / 2;
}
else
{
mid = p[n/2].y;
}
for ( i=0; i<n; i++ )
{
ans += abs ( p[i].y - mid );
}
qsort ( p, n, sizeof ( type ), cmpx );
for ( i=0; i<n; i++ )
{
p[i].x -= i;
}
qsort ( p, n, sizeof ( type ), cmpx );
if ( ! n & 1 )
{
mid = ( p[n/2].x + p[n/2-1].x ) / 2;
}
else
{
mid = p[n/2].x;
}
for ( i=0; i<n; i++ )
{
ans += abs ( p[i].x - mid );
}
printf ( "%d\n", ans );
}
return 0;
}