29 lines
713 B
Python
29 lines
713 B
Python
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# https://en.wikipedia.org/wiki/Ford–Fulkerson_algorithm in O(V^2 * flow)
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def max_flow(cap, s, t):
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def augment_path(cap, visited, i, t):
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if i == t:
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return True
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visited[i] = True
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for j in range(len(cap)):
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if not visited[j] and cap[i][j] > 0 and augment_path(cap, visited, j, t):
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cap[i][j] -= 1
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cap[j][i] += 1
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return True
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return False
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flow = 0
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while True:
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if not augment_path(cap, [False] * len(cap), s, t):
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return flow
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flow += 1
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def test():
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capacity = [[0, 1, 1, 0], [1, 0, 1, 1], [1, 1, 0, 1], [0, 1, 1, 0]]
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assert max_flow(capacity, 0, 3) == 2
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test()
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