hdu 1257 最少拦截系统

。。。不懂为什么这题是DP

#include <cstdio>#include <cstring>#include <iostream>using namespace std;int const MAXN = 100010;int a[MAXN];inline int Max(int a,int b){    return a>b?a:b;}int main(){    int n;    while(~scanf("%d",&n)){        for(int i = 1;i <= n;i++){            scanf("%d",&a[i]);        }        int cnt = 0;        for(int i = 1;i <= n;i++){            int m = a[i];            if(m > 0){                for(int j = i + 1;j <= n;j++){                    if(m > a[j] && a[j]){                        m = a[j];                        a[j] = 0;                        cnt++;                    }                }            }        }        printf("%d\n",n - cnt);    }    return 0;}/*820 16 15 16 13 10 14 102*/