poj1828

找动态规划的题，却找到这道，动态规划该怎么做不知道，只会结构体二级排序。。。

#include <iostream>#include <algorithm>using namespace std;#define N 50002struct Position{int x, y;} monkey[N];bool compare(const Position &a, const Position &b){if(a.x != b.x)return a.x > b.x;else return a.y > b.y;}int main(){int n, i, cnt, tmp;while(scanf("%d", &n) && n){for(i = 0; i < n; i++)scanf("%d%d", &monkey[i].x, &monkey[i].y);sort(monkey, monkey+n, compare);cnt = 1;tmp = monkey[0].y;for(i = 1; i < n; i++){if(monkey[i].y > tmp){cnt++;tmp = monkey[i].y;}}printf("%d\n", cnt);}return 0;}