Submission #685270

#	Time	Username	Problem	Language	Result	Execution time	Memory
685270		White	Star triangles (IZhO11_triangle)	C++14	100 / 100	210 ms	24344 KiB

triangle

#pragma GCC optimize ("O3")
#include <bits/stdc++.h>
#define endl "\n"
using namespace std;

pair<long long,long long>red[300005];
long long ans=0,cnt=0;
vector<long long>x[300005];
map<long long,long long>y;

int main(){

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    long long n;
    cin>>n;
    for(int i=0;i<n;i++){
        long long A,B;
        cin>>A>>B;
        red[i]=make_pair(A+1000000000,B+1000000000);
        y[B+1000000000]++;
    }
    sort(red,red+n);
    x[0].push_back(red[0].second);
    for(int i=1;i<n;i++){
        if(red[i].first==red[i-1].first){
            x[cnt].push_back(red[i].second);
        }else{
            cnt++;
            x[cnt].push_back(red[i].second);
        }
    }

    for(int i=0;i<=cnt;i++){
        for(int j=0;j<x[i].size();j++){
            ans+=(x[i].size()-1)*(y[x[i][j]]-1);
        }
    }
    cout<<ans<<endl;

    return 0;
}

Compilation message (stderr)

triangle.cpp: In function 'int main()':
triangle.cpp:36:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         for(int j=0;j<x[i].size();j++){
      |                     ~^~~~~~~~~~~~

• Subtask 1: 100 / 100