Submission #337506

#	Time	Username	Problem	Language	Result	Execution time	Memory
337506		tengiz05	Star triangles (IZhO11_triangle)	C++17	100 / 100	1036 ms	28384 KiB

triangle

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FASTIO ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define pii pair<int, int>
#define ff first
#define ss second
#define PI acos(-1)
#define ld long double
const int mod = 1e9+7, N = 2e5+5;
int msb(int val){return sizeof(int)*8-__builtin_clzll(val);}
int a[N], n, m, k;
map<int, vector<int>> X, Y;
void solve(int test_case){
	int i, j;
	cin >> n;
	vector<pii> tmp;
	for(i=0;i<n;i++){
		int x, y;
		cin >> x >> y;
		Y[x].pb(y);
		X[y].pb(x);
		tmp.pb({x, y});
	}
	int ans = 0;
	for(auto &[t, tt] : X)sort(all(tt));
	for(auto &[t, tt] : Y)sort(all(tt));
	
	for(auto [x, y] : tmp){
		int itx = lower_bound(all(X[y]), x)-X[y].begin();
		int ity = lower_bound(all(Y[x]), y)-Y[x].begin();
		
		int bx = X[y].size()-itx-1;
		int by = Y[x].size()-ity-1;
		ans += bx*by;
		ans += bx*ity;
		ans += itx*by;
		ans += itx*ity;
	}
	cout << ans << '\n';
	return;
}

signed main(){
	FASTIO;
#define MULTITEST 0
#if MULTITEST
	int ___T;
	cin >> ___T;
	for(int T_CASE = 1; T_CASE <= ___T; T_CASE++)
		solve(T_CASE);
#else
	solve(1);
#endif
	return 0;
}

Compilation message (stderr)

triangle.cpp: In function 'void solve(long long int)':
triangle.cpp:17:9: warning: unused variable 'j' [-Wunused-variable]
   17 |  int i, j;
      |         ^

• Subtask 1: 100 / 100