poj 1065 Wooden Sticks 贪心

#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <iostream>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <stack>
#include <set>
#include <queue>
#include <vector>

using namespace std;

typedef long long ll;

const int maxn = 5100;
const double eps = 1e-7;

struct Node
{
    int x, y;
    bool operator < (const Node &s) const
    {
        if(x == s.x)
            return y < s.y;
        else
            return x < s.x;
    }
}a[maxn];

int flag[maxn];

int main()
{
    //freopen("in.txt", "r", stdin);

    int T;
    scanf("%d", &T);
    while(T--)
    {
        int ans = 0;
        memset(flag, 0, sizeof(flag));

        int n;
        scanf("%d", &n);
        for(int i = 0; i < n; i++)
            scanf("%d%d", &a[i].x, &a[i].y);

        sort(a, a + n);

        int cnt = 0;
        while(cnt < n)
        {
            ans++;
            int pre_x = -1000000;
            int pre_y = -1000000;
            for(int i = 0; i < n; i++)
            {
                if(!flag[i])
                {
                    if(a[i].x >= pre_x && a[i].y >= pre_y)
                    {
                        pre_x = a[i].x;
                        pre_y = a[i].y;
                        cnt++;
                        flag[i] = 1;
                    }
                }
            }
        }

        printf("%d\n", ans);
    }

    return 0;
}