Submission #867675

#	Time	Username	Problem	Language	Result	Execution time	Memory
867675		sleepntsheep	Star triangles (IZhO11_triangle)	C++17	100 / 100	98 ms	4088 KiB

triangle

#include <iostream>
#include <unordered_map>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,tune=native")

using namespace std;
#define ALL(x) x.begin(), x.end()
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false);
using ll = long long;
#define N 300005

int n;
array<int, 2> a[N]; ll z;
unordered_map<int, int> b;

int main()
{
    ShinLena;
    for (int i = (cin >> n, 0); i < n; ++i) cin >> a[i][0] >> a[i][1], ++b[a[i][1]];
    sort(a, a+n); n = unique(a, a+n) - a;
    ll d=0;
    for (int f, e = 0, i = 0, l = -1; i < n; ++i)
    {
        f = a[i][0] == l;
        l += (a[i][0] - l) * !f, d *= f, e *= f;
        z += d + (b[a[i][1]] - 1ll) * e;
        ++e, d += b[a[i][1]] - 1;
    }
    cout << z;
    return 0;
}

• Subtask 1: 100 / 100