#include <bits/stdc++.h>
using namespace std;
#define int long long
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int n;
cin >> n;
vector<pair<int, int> > a(n);
map<int, int> x, y;
for(int i = 0; i < n; i++) {
cin >> a[i].first >> a[i].second;
x[a[i].first]++;
y[a[i].second]++;
}
int ans = 0;
for(int i = 0; i < n; i++) {
ans += x[a[i].first - 1] * y[a[i].first - 1];
}
cout << ans << "\n";
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
