Submission #1112582

#	Time	Username	Problem	Language	Result	Execution time	Memory
1112582		Chinguun	Star triangles (IZhO11_triangle)	C++14	0 / 100	1 ms	592 KiB

triangle

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ff first
#define ss second
#define pb push_back

const int N = 2e5 + 7;
const int oo = 1e18;
const int mod = 1e9 + 7;

typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pii> vii;

int n, x, y, ans;
map <int, vi> mp;
pii p[N];

signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);

	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> x >> y;
		mp[x].pb (y);
		p[y].ff++;
	}
	for (auto it : mp) {
		vi v = it.ss;
		for (int i = 0; i < v.size (); i++) {
			ans += i * (p[v[i]].ss + p[v[i]].ff - 1);
			ans += (v.size () - i - 1) * (p[v[i]].ss + p[v[i]].ff - 1);
			p[v[i]].ff--; p[v[i]].ss++;
		}
	}
	cout << ans;
	return 0;
}

Compilation message (stderr)

triangle.cpp: In function 'int main()':
triangle.cpp:33:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |   for (int i = 0; i < v.size (); i++) {
      |                   ~~^~~~~~~~~~~

• Subtask 1: 0 / 100