Submission #987153

#	Time	Username	Problem	Language	Result	Execution time	Memory
987153		ezzzay	Star triangles (IZhO11_triangle)	C++14	100 / 100	744 ms	34324 KiB

triangle

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ff first
#define ss second
#define pb push_back
const int N=4e5+5;
vector<int>v[N];
signed main(){
    int n;
    cin>>n;
    map<int,int>mpx,mpy,idx,idy;
    vector<pair<int,int>>vc;
    for(int i=1;i<=n;i++){
        int x,y;
        cin>>x>>y;
        vc.pb({x,y});
        idx[x];
        idy[y];
    }
    int e=1,d=1;
    for(auto it=idx.begin();it!=idx.end();it++){
        it->ss =e++;
    }
    for(auto it=idy.begin();it!=idy.end();it++){
        it->ss =d++;
    }
    for(auto p:vc){
        
        int x= idx[p.ff];
        int y=idy[p.ss];
        mpx[x]++;
        mpy[y]++;
        v[x].pb(y);
    }
    
    int cnt=0;
    for(auto it=mpx.begin();it!=mpx.end();it++){
        int x= it->ff;
        for(auto y:v[x]){
            cnt+= (mpy[y]-1)*(mpx[x]-1);
        }
    }
    cout<<cnt;
}

• Subtask 1: 100 / 100