Submission #479274

#	Time	Username	Problem	Language	Result	Execution time	Memory
479274		mewnian	Star triangles (IZhO11_triangle)	C++14	100 / 100	1188 ms	34392 KiB

triangle

#include <bits/stdc++.h>
#define sze(x) (ll)x.size()
#define idx(x, a) get<x>(a)
#define LID(x) (x << 1LL)
#define RID(x) (x << 1LL) + 1LL
#define ID(x) (x + MAXN)
#define CONV(x) (x - MAXN)
#define countbit(x) __builtin_popcountll(x)
#define pb push_back
#define x first
#define y second

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pi;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

ll rand(ll l, ll r)
{
    return uniform_int_distribution<ll>(l, r)(rng);
}

const ll MAXN = 300'003;

ll n;
pi a[MAXN];
map< ll, ll > cx, cy;
map< pi, ll > pts;

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    #ifdef OFFLINE
    freopen("input.inp", "r", stdin);
    #endif
    cin >> n;
    for (ll i = 1; i <= n; ++i)
    {
        cin >> a[i].x >> a[i].y;
        ++cx[a[i].x], ++cy[a[i].y];
        ++pts[a[i]];
    }
    ll res = 0;
    for (ll i = 1; i <= n; ++i)
    {
        res += (cx[a[i].x] - pts[a[i]]) * (cy[a[i].y] - pts[a[i]]);
    }
    cout << res;
}

• Subtask 1: 100 / 100