Submission #88620

#	Time	Username	Problem	Language	Result	Execution time	Memory
88620		toloraia	Star triangles (IZhO11_triangle)	C++17	100 / 100	808 ms	7520 KiB

triangle

#include <bits/stdc++.h>
#define F first
#define S second
#define mp make_pair
#define pb push_back
#define ll long long
#define LEFT(a) ((a)<<1)
#define RIGHT(a) (LEFT(a) + 1)
#define MID(a,b) ((a+b)>>1)
#define MAX(a,b) ((a)>(b)?(a):(b))
#define MIN(a,b) ((a)<(b)?(a):(b))
//#define temo

using namespace std;

const int N = 300007;

map < int, int > M1, M2;
int n;
int x[N], y[N];
ll ans;

int main()
{
    cin>>n;
    for (int i = 1; i <= n; i++){
        cin>>x[i]>>y[i];
        M1[x[i]]++;
        M2[y[i]]++;
    }
    for (int i = 1; i <= n; i++){
        ll p = M1[x[i]] - 1;
        ll q = M2[y[i]] - 1;
        ans += p * q;
    }
    cout<<ans<<endl;
    return 0;
}

• Subtask 1: 100 / 100