Submission #873213

#	Time	Username	Problem	Language	Result	Execution time	Memory
873213		VahanAbraham	Star triangles (IZhO11_triangle)	C++14	100 / 100	233 ms	15520 KiB

triangle

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <sstream>
#include <map>
#include <stack>
#include <set>
#include <queue>
#include <unordered_set>
#include <unordered_map>
#include <math.h>
#include <cmath>
#include <vector>
#include <iomanip>
#include <random>
#include <chrono>
using namespace std;

#define ll long long
#define fr first
#define sc second
#define pb push_back
#define US freopen("milkvisits.in", "r", stdin); freopen("milkvisits.out", "w", stdout);

ll gcd(ll a, ll b)
{
    if (a == 0 || b == 0) {
        return  max(a, b);
    }
    if (a <= b) {
        return gcd(a, b % a);
    }
    else {
        return gcd(a % b, b);
    }
}
ll lcm(ll a, ll b) {
    return (a / gcd(a, b)) * b;
}

const int N = 300005;
const ll oo = 1000000000000000, MOD = 998244353;

pair<ll, ll> p[N];

void solve() {
    int n;
    cin >> n;
    map<ll, ll> mp, kp;
    for (int i = 1; i <= n; ++i) {
        cin >> p[i].fr >> p[i].sc;
        mp[p[i].sc]++;
        kp[p[i].fr]++;
    }
    sort(p + 1, p + n + 1);
    ll ans = 0;
    for (int i = 1; i <= n; ++i) {
        ans += (mp[p[i].sc]-1)*(kp[p[i].fr]-1);
    }
    cout << ans << endl;
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    //US
    int tt = 1;
    //cin >> tt;
    while (tt--) {
        solve();
    }
}

• Subtask 1: 100 / 100