#include <bits/stdc++.h>
#define FOR( i, x, n, d ) for( int i = x; i <= n; i += d )
using namespace std;
const int N = 1e6;
int a[N], b[N], x[N], y[N], a2[N], b2[N], tim;
long long ans = 0;
int main()
{
// freopen("triangle.in", "r", stdin);
// freopen("triangle.out", "w", stdout);
int n; cin >> n;
set <int> st;
map <int, int> mp;
FOR( i, 1, n, 1 ) cin >> x[i] >> y[i], st.insert( x[i] ), st.insert( y[i] );
for( auto i : st ) mp[i] = ++ tim;
FOR( i, 1, n, 1 )
{
x[i] = mp[x[i]], y[i] = mp[y[i]];
b[y[i]] ++;
a2[x[i]] ++;
}
FOR( i, 1, n, 1 )
{
ans += a[x[i]] * 1ll * b[y[i]];
a[x[i]] += b[y[i]];
}
cout << ans / 2;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |