"""
輸入
graph 輸入的圖
src 原點(diǎn)
返回
dis 記錄源點(diǎn)到其他點(diǎn)的最短距離
path 路徑
"""
import json
def dijkstra(graph,src):
  if graph ==None:
    return None
  # 定點(diǎn)集合
  nodes = [i for i in range(len(graph))] # 獲取頂點(diǎn)列表，用鄰接矩陣存儲(chǔ)圖
  # 頂點(diǎn)是否被訪問(wèn)
  visited = []
  visited.append(src)
  # 初始化dis
  dis = {src:0}# 源點(diǎn)到自身的距離為0
  for i in nodes:
    dis[i] = graph[src][i]
  path={src:{src:[]}} # 記錄源節(jié)點(diǎn)到每個(gè)節(jié)點(diǎn)的路徑
  k=pre=src
  while nodes:
    temp_k = k
    mid_distance=float('inf') # 設(shè)置中間距離無(wú)窮大
    for v in visited:
      for d in nodes:
        if graph[src][v] != float('inf') and graph[v][d] != float('inf'):# 有邊
          new_distance = graph[src][v]+graph[v][d]
          if new_distance <= mid_distance:
            mid_distance=new_distance
            graph[src][d]=new_distance # 進(jìn)行距離更新
            k=d
            pre=v
    if k!=src and temp_k==k:
      break
    dis[k]=mid_distance # 最短路徑
    path[src][k]=[i for i in path[src][pre]]
    path[src][k].append(k)

    visited.append(k)
    nodes.remove(k)
    print(nodes)
  return dis,path
if __name__ == '__main__':
  # 輸入的有向圖,有邊存儲(chǔ)的就是邊的權(quán)值，無(wú)邊就是float('inf')，頂點(diǎn)到自身就是0
  graph = [ 
    [0, float('inf'), 10, float('inf'), 30, 100],
    [float('inf'), 0, 5, float('inf'), float('inf'), float('inf')],
    [float('inf'), float('inf'), 0, 50, float('inf'), float('inf')],
    [float('inf'), float('inf'), float('inf'), 0, float('inf'), 10],
    [float('inf'), float('inf'), float('inf'), 20, 0, 60],
    [float('inf'), float('inf'), float('inf'), float('inf'), float('inf'), 0]]
  dis,path= dijkstra(graph, 0) # 查找從源點(diǎn)0開(kāi)始帶其他節(jié)點(diǎn)的最短路徑
  print(dis)
  print(json.dumps(path, indent=4))