72 lines
2.5 KiB
Forth
72 lines
2.5 KiB
Forth
(*
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Copyright 2010-2017 Google
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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Answer:
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Solving max flow with 6 nodes, and 9 arcs, source=0, sink=5
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total computed flow 10, expected = 10
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Arc 1 (1 -> 0), capacity=5, computed=4, expected=4
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Arc 2 (2 -> 0), capacity=8, computed=4, expected=4
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Arc 3 (3 -> 0), capacity=5, computed=2, expected=2
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Arc 4 (4 -> 0), capacity=3, computed=0, expected=0
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Arc 5 (3 -> 1), capacity=4, computed=4, expected=4
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Arc 6 (4 -> 2), capacity=5, computed=4, expected=4
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Arc 7 (4 -> 3), capacity=6, computed=0, expected=0
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Arc 8 (5 -> 3), capacity=6, computed=6, expected=6
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Arc 9 (5 -> 4), capacity=4, computed=4, expected=4
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*)
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#I "../../bin"
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#I "./packages/NETStandard.Library.2.0.2/build/netstandard2.0/ref"
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#r "Google.OrTools.dll"
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#r "Google.OrTools.FSharp.dll"
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#r "netstandard.dll"
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open Google.OrTools.Graph
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open Google.OrTools.FSharp
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printfn "Max Flow Problem"
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let numNodes = 6;
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let numArcs = 9;
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let tails = [0; 0; 0; 0; 1; 2; 3; 3; 4]
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let heads = [1; 2; 3; 4; 3; 4; 4; 5; 5]
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let capacities = [5L; 8L; 5L; 3L; 4L; 5L; 6L; 6L; 4L]
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let expectedFlows = [4; 4; 2; 0; 4; 4; 0; 6; 4]
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let expectedTotalFlow = 10;
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let maxFlow = new MaxFlow()
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for i=0 to (numArcs-1) do
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let arc = maxFlow.AddArcWithCapacity(tails.[i], heads.[i], capacities.[i])
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if (arc <> i) then
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failwith "Internal error"
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let source = 0;
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let sink = numNodes - 1;
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printfn "Solving max flow with %i nodes, and %i arcs, source=%i, sink=%i " numNodes numArcs source sink
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let solveStatus = maxFlow.Solve(source, sink)
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match solveStatus with
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| x when x = MaximumFlowResult.Optimal.Id ->
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let totalFlow = maxFlow.OptimalFlow();
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printfn "total computed flow %i, expected = %i" totalFlow expectedTotalFlow
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for i=1 to numArcs do
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printfn "Arc %i (%i -> %i), capacity=%i, computed=%i, expected=%i" i (maxFlow.Head(i-1)) (maxFlow.Tail(i-1)) (maxFlow.Capacity(i-1)) (maxFlow.Flow(i-1)) (expectedFlows.[i-1])
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| _ ->
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printfn "Solving the max flow problem failed. Solver status: %i" solveStatus
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