# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
91065 | quotitquot | Star triangles (IZhO11_triangle) | C++98 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#define fr first
#define sc scanf
#define pf printf
#define se second
#define sq(x) x * x
#define ll long long
#define pb push_back
#define mk make_pair
#define ld long double
#define pr pair<ll,ll>
#define sz(s) int(s.size())
#define piip pair< pair<ll,ll>,ll >
//#define fin(s) freopen( s, "r", stdin )
//#define fout(s) freopen( s, "w", stdout )
#define TIME ios_base::sync_with_stdio(0)
using namespace std;
const ll INF = 1e9;
const ll N = 1e5 + 1;
const ll mod = 1e9 + 7;
const long double eps = 1E-7;
map<ll,ll>l, r;
ll n, x[N], y[N], ans;
int main()
{
TIME;
freopen( "triangles.in", "r", stdin )
freopen( "triangles.out", "w", stdout )
cin >> n;
for( int i = 1; i <= n; i ++ )
{
cin >> x[i] >> y[i];
l[x[i]] ++, r[y[i]] ++;
}
for( int i = 1; i <= n; i ++ )
ans += (l[x[i]]-1) * (r[y[i]]-1);
cout << ans << endl;
}