$ python3 my_dijkstra.py 
頂点0から頂点2への経路: 0 4 1 2 
0, adj = {1: 15, 4: 7}, 0, None
1, adj = {2: 1, 4: 3}, 11, 4
2, adj = {3: 5}, 12, 1
3, adj = {2: 6, 0: 9}, 9, 4
4, adj = {1: 4, 2: 11, 3: 2}, 7, 0