提出 #11960055

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ソースコード 拡げる

#include <string.h>
#include <iostream>
#include <vector>
#include <bitset>
#include <algorithm>
#include <cmath>

using namespace std;
typedef long long unsigned int ll;

#define N 8

int main() {
    int n = 0;
    double x[N];
    double y[N];

    
    cin >> n;

    for(int i = 0; i < n; i++){
        cin >> x[i] >> y[i];
    }
    vector<int> order(n);
    for (int i = 0; i < n; i++) order[i] = i;

    double res = 0.0;
    double cnt = 0;
    do {
        double sum = 0;
        for (int i = 1; i < n; ++i) {
            double x_ = x[order[i-1]]-x[order[i]];
            double y_ = y[order[i-1]]-y[order[i]];
            double tmp = std::sqrt(x_ * x_+ y_ * y_);
            sum += tmp;
            //cout << std::fixed << tmp << endl;
        }

        res += sum;
        //cout << std::fixed << res << endl;
        cnt++;

    } while (next_permutation(order.begin(), order.end()));
    cout << std::fixed << res/cnt  << endl;

}

提出情報

ジャッジ結果