Submission #8471859

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Source Code Expand

#include <cstdio>
#include <algorithm>
#include <cmath>

using namespace std;

const int N = 9;

int x[N];
int y[N];
int p[N];

int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) {
    scanf("%d%d", x + i, y + i);
    p[i] = i;
  }
  double ans = 0;
  do {
    for (int i = 0; i < n - 1; ++i) {
      ans += sqrt((x[p[i]] - x[p[i + 1]]) * (x[p[i]] - x[p[i + 1]]) + (y[p[i]] - y[p[i + 1]]) * (y[p[i]] - y[p[i + 1]]));
    }
  } while (next_permutation(p, p + n));
  for (int i = 2; i <= n; ++i) {
    ans /= i;
  }
  printf("%.15f\n", ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:15:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
                  ^
./Main.cpp:17:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", x + i, y + i);
                                ^

Judge Result