Pravokutni

#include<bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
#define debug(...) #__VA_ARGS__ << ": " << __VA_ARGS__
using ii=long long;

#define x real()
#define y imag()

using pi=pair<int,int>;
using C=complex<ii>;

int clock_wise(C a, C c)
{
    C b = {0, 0};
    return ((c - a) * conj(b - a)).y > 0;
}

C points[1555];

// a ^ 2 + b ^ 2 = c ^ 2

// a ^ 2 + b ^ 2 < c ^ 2

ii dist(C a, C b)
{
    ii ax = a.x - b.x;
    ii ay = a.y - b.y;
    return ax * ax + ay * ay;
}

int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        ii ax;
        ii ay;
        cin >> ax >> ay;
        points[i] = {ax, ay};
    }
    int r = 0;
    for (int i = 0; i < n; ++i) {
        vector<C> p;
        for (int j = 0; j < n; ++j) {
            if (i == j) continue;
            p.push_back(points[i] - points[j]);
        }
        sort(all(p), [&](C a, C b)
        {
            return clock_wise(a, b) < clock_wise(b, a);
        }
        );
        C z = {0, 0};
        for (int i = 0; i < n - 1; ++i) {
            for (int j = 0; j < i; ++j) {
                if (dist(z, p[i]) + dist(z, p[j]) == dist(p[i], p[j])) r++;
            }
        }
    }
    cout << r << "\n";
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: TIME LIMIT EXCEEDED

Test 7

Verdict: TIME LIMIT EXCEEDED

Test 8

Verdict: TIME LIMIT EXCEEDED

Test 9

Verdict: TIME LIMIT EXCEEDED

Test 10

Verdict: TIME LIMIT EXCEEDED