Submission #481520

#	Time	Username	Problem	Language	Result	Execution time	Memory
481520		Kalashnikov	Star triangles (IZhO11_triangle)	C++17	100 / 100	876 ms	30952 KiB

triangle

#include <bits/stdc++.h>
 
#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define all(a) a.begin() , a.end()
#define F first
#define S second
 
using namespace std;
using ll = long long;
 
const int N = 3e5+5 , inf = 2e9 + 7;
const ll INF = 1e18 ,   mod = 1e9+7 , P = 6547;

int x[N] , y[N];

void solve(int tc) {
	int n;
	cin >> n;
	map<int,int> cntx , cnty;
	map<pair<int,int>,int> cnt;
	for(int i= 1; i <= n; i ++) {
		cin >> x[i] >> y[i];
		cntx[x[i]] ++;
		cnty[y[i]] ++;
		cnt[{x[i] , y[i]}] ++;
	}
	ll ans = 0;
	for(int i = 1; i <= n; i ++) {
		int X = cntx[x[i]] - cnt[{x[i] , y[i]}];
		int Y = cnty[y[i]] - cnt[{x[i] , y[i]}];
		ans += 1ll*X*Y*cnt[{x[i] , y[i]}];
	}
	cout << ans;
}
/*
*/
main() {
	file("triangles");
    ios;
    int tt = 1 , tc = 0;
    // cin >> tt;
    while(tt --) {
        solve(++tc);
    }
    return 0;
}

Compilation message (stderr)

triangle.cpp:38:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   38 | main() {
      | ^~~~
triangle.cpp: In function 'int main()':
triangle.cpp:4:48: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    4 | #define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
      |                                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~
triangle.cpp:39:2: note: in expansion of macro 'file'
   39 |  file("triangles");
      |  ^~~~
triangle.cpp:4:77: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    4 | #define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
      |                                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
triangle.cpp:39:2: note: in expansion of macro 'file'
   39 |  file("triangles");
      |  ^~~~

• Subtask 1: 100 / 100