p1828.cpp

大概POJ上50道比较难的题的代码

#include <iostream>
#include <algorithm>
using namespace std;
const int MAXN = 50001;
struct point{ int x,y; };
point a[MAXN];
bool cmp(point a,point b){ return a.x > b.x || a.x == b.x && a.y > b.y; }
int main(){
    int n;
    while(cin >> n && n){
        for(int i = 0;i < n;++i) scanf("%d%d",&a[i].x,&a[i].y);
        sort(a,a+n,cmp);
        int maxy = a[0].y,ans = 1;
        for(int i = 1;i < n;++i)
            if(a[i].x != a[i-1].x && a[i].y > maxy){
                ++ans;
                maxy = a[i].y;
            }
        printf("%d\n",ans);
    }
}