What is wrong with my implementation of Dijkstra's algorithm?

Question

C++ / C#

There is a task: to write a program that calculates the minimum distances to the vertices in a graph using Dijkstra's method. Test on graphs with 5000 and 9000 vertices. Wrote code:

#include <cstdlib>
#include <iostream>
#include <iomanip>

using namespace std;

int main() {
  const int inf = 1000000;
  srand(time(NULL));
  int n;
  cout << "Enter the number of vertices:" << endl;
  cin >> n;
  int **w;
  w = new int *[n];
  for (int i = 0; i < n; i++) {
    w[i] = new int[n];
  }
  
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      w[i][j] = 0;
      w[i][j] = rand() % 100;
    }
  }
  
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      if (i == j) w[i][j] = 0;
      else w[i][j] = w[j][i];
    }
  }
  
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      cout << setw(5) << w[i][j];
    }
    cout << endl;
  }
  
  int *d = new int [n];
  int *v = new int [n];
  
  for (int i = 0; i < n; i++) {
    d[i] = inf;
    v[i] = 1;
  }
  
  cout << "Enter the number of the vertex for which you want to find distances: ";
  int ind;
  cin >> ind;
  ind--;
  d[ind] = 0;
  
  int minIndex, min, temp, counter = 0;
  
  do {
    minIndex = inf;
    min = inf;
    
    for (int i = 0; i < n; i++) {
      if((v[i] == 1) && (d[i] < min)) {
        min = d[i];
        minIndex = i;
      }
    }
    
    if (minIndex != inf) {
      for (int i = 0; i < n; i++) {
        if (w[minIndex][i] > 0) {
          temp = min + w[minIndex][i];
          if (temp < d[i]) {
            d[i] = temp;
          }
        }
        counter++;
      }
      v[minIndex] = 0;
    }
  } while (minIndex < inf);
  
  for (int i = 0; i < n; i++) {
    cout << setw(5) << d[i];
  }
  cout << endl;
  cout << "Number of iterations: " << counter << endl;
  system("pause");
  return 0;
}

But all distances are in the range 1-4. I tried to run 100 vertices, in this case it is normal. What could be the problem?

Answer 1

Look at this code