Submission #856491

#	Time	Username	Problem	Language	Result	Execution time	Memory
856491		aykhn	Star triangles (IZhO11_triangle)	C++14	100 / 100	681 ms	37672 KiB

triangle

#include <bits/stdc++.h>

// author : aykhn

using namespace std;
typedef long long ll;

#define pb push_back
#define ins insert
#define mpr make_pair
#define all(v) v.begin(), v.end()
#define bpc __builtin_popcount
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
#define int ll
#define infll 0x3F3F3F3F3F3F3F3F
#define inf 0x3F3F3F3F

map<pii, int> mp;
signed main()
{
    int n;
    cin >> n;
    vector<int> x, y;
    vector<pii> c;
    for (int i = 0; i < n; i++)
    {
        int a, b;
        cin >> a >> b; 
        c.pb(mpr(a, b));
        x.pb(a);
        y.pb(b);
        mp[mpr(a, b)]++;
    }
    sort(all(x));
    sort(all(y));
    int res = 0;
    for (int i = 0; i < n; i++)
    {
        int c1 = upper_bound(all(x), c[i].fi) - lower_bound(all(x), c[i].fi);
        int c2 = upper_bound(all(y), c[i].se) - lower_bound(all(y), c[i].se);
        c1 -= mp[c[i]];
        c2 -= mp[c[i]];
        res += c1 * c2;
    }
    cout << res << '\n';
    
}

• Subtask 1: 100 / 100