INT102-Bellman-Ford Algorithm

 1 INF = 10000
 2 
 3 
 4 def getGraph() -> tuple:
 5     G = [
 6         #a  b  c  d   e
 7         [0, 4, 5, 0,  0],  # a
 8         [0, 0, 0, 8,  0],  # b
 9         [0, 0, 0, 0, -7],  # c
10         [0, 0, 0, 0, -6],  # d
11         [0, 2, 0, 0,  0]   # e
12     ]
13     return G, 5
14 
15 
16 def bellman(G: list, n: int, s: int):
17     dis = [INF for _ in range(n)]
18     dis[s] = 0 # start from a
19     for _ in range(n - 1):
20         for i in range(n):
21             for j in range(n):
22                 if G[i][j] != 0 and dis[j] > dis[i] + G[i][j]:
23                     dis[j] = dis[i] + G[i][j]
24     return dis
25 
26 
27 if __name__ == '__main__':
28     G, n = getGraph()
29     dis = bellman(G, n, 0)
30     print(dis)
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