Submission #901892

#	Time	Username	Problem	Language	Result	Execution time	Memory
901892		Iwantbemaster	Star triangles (IZhO11_triangle)	C++17	100 / 100	254 ms	20404 KiB

triangle

	#include <bits/stdc++.h>
	using namespace std;
	#define int long long
	#define ff first
	#define ss second
	#pragma GCC optimize("Ofast","inline","-ffast-math")
	main(){
		int n, ans = 0; cin >> n; map<int, int> x, y;
		vector<pair<int, int>> res;
		for(int i = 0; i < n; i++){
			int x1, y1; cin >> x1 >> y1;
			x[x1]++, y[y1]++; res.emplace_back(x1, y1);
		} for(auto p : res) ans += (x[p.ff]-1) * (y[p.ss]-1);
		cout << ans;
	}
	const int fastIO = [](){
		ios_base::sync_with_stdio(false);
		cin.tie(nullptr); cout.tie(nullptr);
		return 0;
	}();
	//  - 32 !- 33 "- 34 #- 35 $- 36 %- 37 &- 38 '- 39 (- 40 )- 41 *- 42 +- 43 ,- 44 -- 45 .- 46 /- 47 
	// 0- 48 1- 49 2- 50 3- 51 4- 52 5- 53 6- 54 7- 55 8- 56 9- 57 :- 58 ;- 59 <- 60 =- 61 >- 62 ?- 63 
	// @- 64 A- 65 B- 66 C- 67 D- 68 E- 69 F- 70 G- 71 H- 72 I- 73 J- 74 K- 75 L- 76 M- 77 N- 78 O- 79 
	// P- 80 Q- 81 R- 82 S- 83 T- 84 U- 85 V- 86 W- 87 X- 88 Y- 89 Z- 90 [- 91 \- 92 ]- 93 ^- 94 _- 95 
	// `- 96 a- 97 b- 98 c- 99 d-100 e-101 f-102 g-103 h-104 i-105 j-106 k-107 l-108 m-109 n-110 o-111 
	// p-112 q-113 r-114 s-115 t-116 u-117 v-118 w-119 x-120 y-121 z-122 {-123 |-124 }-125 ~-126 -127

Compilation message (stderr)

triangle.cpp:7:2: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    7 |  main(){
      |  ^~~~

• Subtask 1: 100 / 100