diff --git a/floyd_warshall.py b/floyd_warshall.py new file mode 100644 index 0000000..4a901d8 --- /dev/null +++ b/floyd_warshall.py @@ -0,0 +1,42 @@ +import math + + +class Graph: + def __init__(self, N=0): # a graph with Node 0,1,...,N-1 + self.N = N + self.W = [ + [math.inf for j in range(0, N)] for i in range(0, N) + ] # adjacency matrix for weight + self.dp = [ + [math.inf for j in range(0, N)] for i in range(0, N) + ] # dp[i][j] stores minimum distance from i to j + + def addEdge(self, u, v, w): + self.dp[u][v] = w + + def floyd_warshall(self): + for k in range(0, self.N): + for i in range(0, self.N): + for j in range(0, self.N): + self.dp[i][j] = min(self.dp[i][j], self.dp[i][k] + self.dp[k][j]) + + def showMin(self, u, v): + return self.dp[u][v] + + +if __name__ == "__main__": + graph = Graph(5) + graph.addEdge(0, 2, 9) + graph.addEdge(0, 4, 10) + graph.addEdge(1, 3, 5) + graph.addEdge(2, 3, 7) + graph.addEdge(3, 0, 10) + graph.addEdge(3, 1, 2) + graph.addEdge(3, 2, 1) + graph.addEdge(3, 4, 6) + graph.addEdge(4, 1, 3) + graph.addEdge(4, 2, 4) + graph.addEdge(4, 3, 9) + graph.floyd_warshall() + graph.showMin(1, 4) + graph.showMin(0, 3)