제출 #342392

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
342392		IZhO_2021_I_want_Silver	별들과 삼각형 (IZhO11_triangle)	C++14	100 / 100	519 ms	15756 KiB

triangle

#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <iomanip>
#include <cassert>
#include <stack>
#include <queue>
#include <deque>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>-

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;

// template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
//  order_of_key (k) : Number of items strictly smaller than k .
//  find_by_order(k) : K-th element in a set (counting from zero).
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define pb push_back
#define ppb pop_back
#define mkp make_pair
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define show(a) cerr << #a <<" -> "<< a <<" "
#define nl cerr <<"\n"
#define int ll

const int N = 3e5 + 5;
const int oo = 1e9 + 5;

int n, x[N], y[N], ans;
map <int, int> cntx, cnty;

void solve() {
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        cin >> x[i] >> y[i];
        ++cntx[x[i]];
        ++cnty[y[i]];
    }
    for (int i = 1; i <= n; ++i) {
        //show(x[i]); show(y[i]); nl;
        //show(cnt[x[i]]); show(cnt[y[i]]); nl;
        ans += (cntx[x[i]] - 1) * (cnty[y[i]] - 1);
    }
    cout << ans;
}

 main () {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int tests = 1;
	//cin >> tests;
	while (tests --) {
		solve();
	}
	return 0;
}
/*
    Just Chalish!
*/

컴파일 시 표준 에러 (stderr) 메시지

triangle.cpp:59:8: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   59 |  main () {
      |        ^

• Subtask 1: 100 / 100