Submission #1122951

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122951		marinaluca	Star triangles (IZhO11_triangle)	C++20	100 / 100	295 ms	9240 KiB

triangle

#include <bits/stdc++.h>

#pragma GCC optimize ("O3")
#pragma GCC optimize ("fast-math")
#pragma GCC optimize ("unroll-loops")

using namespace std;
#define int long long
#define ll long long
#define all (x) begin(x), end (x)
#define xx first
#define yy second

using pii = pair <int, int>;
using tii = tuple <int, int, int>;

int n;
constexpr int NMAX = (int) 3e5;

int v[NMAX + 1], w[NMAX + 1];
map <int, int> frec, frec1;
int s;
signed main(void)
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n;
    for (int i = 1; i <= n; ++ i)
    {
        cin >> v[i] >> w[i];
        frec[v[i]] ++;
        frec1[w[i]] ++;
    }
    for (int i = 1; i <= n; ++ i)
    {
        s += (frec[v[i]] - 1) * (frec1[w[i]] - 1);
    }
    cout << s;
    return 0 ^ 0;
}

• Subtask 1: 100 / 100