Submission #887205

#	Time	Username	Problem	Language	Result	Execution time	Memory
887205		abushbandit_1	Star triangles (IZhO11_triangle)	C++17	0 / 100	1 ms	348 KiB

triangle

/*

author : abushbandit
contest : ---

*/

#include "bits/stdc++.h"

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;

using namespace std;

#define int long long
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define ff first
#define ss second
#define pb push_back
#define rep(i,s,f) for(int i = s;i < f;i++)

#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>

#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast,unroll-loops")

template <class type1>
	using ordered_multiset = tree <type1, null_type, less_equal <type1>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<pair<int,int>> vii;
typedef pair<int,int> pii;

const ll INF = 1e18;
const ll MOD7 = 1e9 + 7;
const ll MOD9 = 998244353;
const ld PI = acos(-1.0);
const int N = 1e5 + 2;

template <class F, class _S>
bool chmin(F &u, const _S &v){
    bool flag = false;
    if ( u > v ){
        u = v; flag |= true;
    }
    return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
    bool flag = false;
    if ( u < v ){
        u = v; flag |= true;
    }
    return flag;
}

int binpow (int a, int n) {
	int res = 1;
	while (n) {
		if (n & 1)
			res *= a;
		a *= a;
		n >>= 1;
	}
	return res;
}

void start_file(string file){
	freopen((file + ".in").c_str(),"r",stdin);
	freopen((file + ".out").c_str(),"w",stdout);
}

bool isRightTriangle(double x1, double y1, double x2, double y2, double x3, double y3) {
    double a = pow(x2 - x1, 2) + pow(y2 - y1, 2);
    double b = pow(x3 - x1, 2) + pow(y3 - y1, 2);
    double c = pow(x3 - x2, 2) + pow(y3 - y2, 2);

    double maxSide = max({a, b, c});

    if (maxSide == c) {
        return c == a + b;
    } else if (maxSide == a) {
        return a == b + c;
    } else {
        return b == a + c;
    }
}

void solve(int tc){

	int n;
	cin >> n;
	vector<int> x(n),y(n);
	rep(i,0,n){
		cin >> x[i] >> y[i];
	}
	int cnt = 0;
	rep(i,0,n){
		rep(j,i + 1,n){
			rep(k,j + 1,n){
				cnt += isRightTriangle((double)x[i],(double)y[i],(double)x[j],(double)y[j],(double)x[k],(double)y[k]);
			}
		}
	}
	cout << cnt;
	 
}

signed main(){

//	start_file("");

	ios_base::sync_with_stdio(0);
	cin.tie(0);cout.tie(0);

	int test_cases = 1;
//	cin >> test_cases ;
	for(int tc = 1;tc <= test_cases;++ tc){
		solve(tc);
	}

}

/*



*/

Compilation message (stderr)

triangle.cpp: In function 'void start_file(std::string)':
triangle.cpp:75:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |  freopen((file + ".in").c_str(),"r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
triangle.cpp:76:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |  freopen((file + ".out").c_str(),"w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 100