Submission #867670

#	Time	Username	Problem	Language	Result	Execution time	Memory
867670		sleepntsheep	Star triangles (IZhO11_triangle)	C++17	100 / 100	175 ms	6992 KiB

triangle

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

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, c[N<<1], C, b[N<<1];
array<int, 2> a[N]; ll z;

int main()
{
    ShinLena;
    for (int i = (cin >> n, 0); i < n; ++i) cin >> a[i][0] >> a[i][1], c[C++] = a[i][0], c[C++] = a[i][1];
    sort(c, c+C); C = unique(c, c+C) - c;
    for (int i = 0; i < n; ++i) 
    {
        for (int j = 0; j < 2; ++j) a[i][j] = lower_bound(c, c+C, a[i][j]) - c;
        ++b[a[i][1]];
    }
    sort(a, a+n); n = unique(a, a+n) - a;
    for (ll e = 0, d = 0, i = 0, l = -1; i < n; ++i)
    {
        if (a[i][0] != l) l = a[i][0], d = 0, e = 0;
        z += d + (b[a[i][1]] - 1ll) * e;
        ++e, d += b[a[i][1]] - 1;
    }
    cout << z;
    return 0;
}

• Subtask 1: 100 / 100