201912-2 回收站选址

#include<iostream>
#include<cstdio>
#include<set>
using namespace std;
struct Point {
    int x,y;
    Point(int _x,int _y):x(_x),y(_y){}
    bool operator <(  const Point &rhs) const {
        if(x==rhs.x) return y<rhs.y;
        return  x<rhs.x;
    }
};
int n;
int ans[5];
set<Point> pts;
bool find(int x,int y){
    if(pts.find(Point(x,y))!=pts.end()) return true;
    return false;
}
int main(){
    int x,y;
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>x>>y;
        pts.insert(Point(x,y));
    }
    set<Point>::iterator it;
    for(it=pts.begin();it!=pts.end();it++){
        x=(*it).x;
        y=(*it).y;
        if(find(x, y+1) && find(x, y-1) && find(x+1, y) && find(x-1, y)){
            int cnt=0;
                        if(find(x-1, y+1)) cnt++;
                        if(find(x+1, y+1)) cnt++;
                        if(find(x-1, y-1)) cnt++;
                        if(find(x+1, y-1)) cnt++;
                        ans[cnt]++;
            
        }
    }
    for(int i=0;i<5;i++){
        cout<<ans[i]<<endl;
    }
    return 0;
}