1548.txt

北大ACM题目例程 详细的解答过程 程序实现 算法分析

#include <stdio.h>
int x[1000], y[1000];
bool sign[1000];

int main()
{
        int a, b, n, m, i, ans;
        while( 1 )
        {
                n = 0;
                while( 1 )
                {
                        scanf( "%d %d", &x[n], &y[n] );
                        if( x[n] < 0 && y[n] < 0 ) return 0;
                        if( x[n] == 0 && y[n] == 0 ) break;
                        sign[n] = false;
                        n++;
                }
                
                for( m=0, ans = 0; m<n; ans++ )
                {
                        a = 0, b= 0;
                        for( i=0; i<n; i++ )
                        if( !sign[i] && x[i]>=a && y[i] >=b )
                        {
                                sign[i] = true;
                                m++;
                                a = x[i], b = y[i];
                         }
                }
                
                printf( "%d\n", ans );
        }
        return 0;
}