问求最小权重Dijkstra树

EN

 shortestPath(G, A, D, prev[])
      for v in G.V
          dist[v] = infinity
          prev[v] = -1 // no parent (assumes nodes are positive integers)
      dist[A] = 0
      for v in G.V
          Q.insert(v, dist[v])
      while Q not empty
          u = Q.deleteMin()
          if dist[u] >= infinity
              return false  // no path to u
          if u == D
              return true   // found path (don't stop if you want the whole tree)
          for all v adjacent to u
              let d = dist[u] + v.weight
              if d < dist[v]
                  dist[v] = d
                  prev[v] = u // update parent
                  Q.decreaseKey(v, d)

  v = D
  while v >= 0
     path.addFirst(v)
     v = prev[v]