最少拦截系统

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main( )
{
    int dp[10000];
    int N, i, j, num, t;
    while (scanf("%d", &N) != EOF )
    {   
        num = 0;

        for (i = 0; i < N; i++)
            scanf("%d",&dp[i]);
        for (i = 0; i < N; i++) {
            if (dp[i] != -1) {
            t = dp[i], dp[i] = -1;
            for (j = i + 1; j < N; j++)
                if (dp[j] != -1 && t > dp[j]) {
                    t = dp[j];
                    dp[j] = -1;
                }
           num++;
          }
       }
        printf("%d\n",num);
    }
    return 0;
}