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43 lines
1.2 KiB
Python
43 lines
1.2 KiB
Python
import math
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class Graph:
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def __init__(self, N=0): # a graph with Node 0,1,...,N-1
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self.N = N
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self.W = [
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[math.inf for j in range(0, N)] for i in range(0, N)
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] # adjacency matrix for weight
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self.dp = [
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[math.inf for j in range(0, N)] for i in range(0, N)
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] # dp[i][j] stores minimum distance from i to j
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def addEdge(self, u, v, w):
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self.dp[u][v] = w
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def floyd_warshall(self):
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for k in range(0, self.N):
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for i in range(0, self.N):
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for j in range(0, self.N):
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self.dp[i][j] = min(self.dp[i][j], self.dp[i][k] + self.dp[k][j])
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def showMin(self, u, v):
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return self.dp[u][v]
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if __name__ == "__main__":
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graph = Graph(5)
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graph.addEdge(0, 2, 9)
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graph.addEdge(0, 4, 10)
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graph.addEdge(1, 3, 5)
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graph.addEdge(2, 3, 7)
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graph.addEdge(3, 0, 10)
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graph.addEdge(3, 1, 2)
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graph.addEdge(3, 2, 1)
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graph.addEdge(3, 4, 6)
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graph.addEdge(4, 1, 3)
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graph.addEdge(4, 2, 4)
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graph.addEdge(4, 3, 9)
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graph.floyd_warshall()
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graph.showMin(1, 4)
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graph.showMin(0, 3)
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