Bellman Ford 2

#include <iostream>
#include <queue>
#include <cmath>
#include <vector>

using namespace std;

typedef double T;
typedef vector<T> VT;
typedef vector<VT> VVT;

typedef vector<int> VI;
typedef vector<VI> VVI;

bool BellmanFord (const VVT &w, VT &dist, VI &prev, int start){
  int n = w.size();
  prev = VI(n, -1);
  dist = VT(n, 1000000000);
  dist[start] = 0;

  for (int k = 0; k < n; k++){
    for (int i = 0; i < n; i++){
      for (int j = 0; j < n; j++){
        if (dist[j] > dist[i] + w[i][j]){
          if (k == n-1) return false;
          dist[j] = dist[i] + w[i][j];
          prev[j] = i;
        }
      }
    }
  }

  return true;
}