PRIMA s

#include <iostream>
#include <cmath>
#include <vector>
using namespace std;
const int INF = 1e9;
struct Point{
  int x;
  int y;
};
double diistance(int x1, int y1, int x2, int y2){
  double a = x1;
  double b = x2;
  double c = y1;
  double d = y2;
  return sqrt(pow(a - b,2)/1.0 + pow(c - d,2)/1.0);
}

int main() {
  int n;
  cin >> n;
  Point vertexes[5000];
  for (int i = 0; i < n; ++i){
    int x;
    int y;
    cin >> x >> y;
    Point a;
    a.x = x;
    a.y = y;
    vertexes[i] = a;
  }
  vector <double> d(n*(n-1)/2,INF);
  bool used[5000];
  int p[5000];
  for (int i = 0; i < 5000; ++i){
    used[i] = false;
    p[i] = -1;
  }
  d[0] = 0;
  int last_v;
  for (int i = 0; i < n; ++i){
    int v = -1;
    for (int j = 0; j < n - 1; ++j){
      if (!used[j] && (v == -1 || d[v] > d[j]))
        v = j;
      used[v] = true;
      for (int z = 0; z < n; ++z){
        int u = z;
        double w = diistance(vertexes[v].x,vertexes[v].y,vertexes[u].x,vertexes[u].y);
        if (!used[u] && d[u] > w && u!= v){
          d[u] = w;
          p[u] = v;
          last_v = u;
          cout << "Расстояние из вершины " << v << " в вершину " << u <<" равно " << w << endl;
        }
      }
    }
  }
  double summ = 0;
  for (int i = 0; i < n; ++i){
    cout << d[i] << endl;
  }
  cout << summ;
}