Adding Knapsack example

.gitignore

@@ -70,5 +70,5 @@ tools/docker/export
 .idea/*
 .idea/
 build/
-
+**/.vscode/*
 .DS_Store

examples/fsharp/knapsack.fsx

@@ -0,0 +1,32 @@
+(*
+
+Copyright 2010-2017 Google
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+*)
+
+#I "./lib"
+#load "Google.OrTools.FSharp.fsx"
+
+open Google.OrTools.FSharp
+
+let profits = [ 360L; 83L; 59L; 130L; 431L; 67L; 230L; 52L; 93L; 125L; 670L; 892L; 600L; 38L; 48L; 147L; 78L; 256L; 63L; 17L; 120L; 164L; 432L; 35L; 92L; 110L; 22L; 42L; 50L; 323L; 514L; 28L; 87L; 73L; 78L; 15L; 26L; 78L; 210L; 36L; 85L; 189L; 274L; 43L; 33L; 10L; 19L; 389L; 276L; 312L ]
+let weights = [ 7L; 0L; 30L; 22L; 80L; 94L; 11L; 81L; 70L; 64L; 59L; 18L; 0L; 36L; 3L; 8L; 15L; 42L; 9L; 0L; 42L; 47L; 52L; 32L; 26L; 48L; 55L; 6L; 29L; 84L; 2L; 4L; 18L; 56L; 7L; 29L; 93L; 44L; 71L; 3L; 86L; 66L; 31L; 65L; 0L; 79L; 20L; 65L; 52L; 13L ]
+let capacities = [ 850L ]
+
+printfn "Solving knapsack with %i items and %i dimensions" (profits.Length) (weights.Length)
+
+let ks = knapsackSolve "test" KnapsackSolverAlgorithm.MultidimensionBranchAndBound profits weights capacities
+let computedProfit = ks.Solve();
+let expectedProfit = 7534L
+printfn "Optimal Profit = %d \nexpected = %d \nOptimal Soltion = %b " computedProfit expectedProfit (ks.IsSolutionOptimal())

examples/fsharp/lib/Google.OrTools.FSharp.fsx

@@ -3,6 +3,7 @@
 #r "Google.OrTools.dll"
 
 open System
+open Google.OrTools.Algorithms
 open Google.OrTools.LinearSolver
 
 type Goal =
@@ -89,6 +90,8 @@ module MaximumFlow =
       BadInput
     | 3 ->
       BadResult
+    | unknownResult ->
+      failwithf "Unknown result %i" unknownResult
 
 /// Minimum Cost Flow Result
 module MinimumCostFlow =
@@ -108,6 +111,63 @@ module MinimumCostFlow =
       BadResult
     | 6 ->
       BadCostRange
+    | unknownResult ->
+      failwithf "Unknown result %i" unknownResult
+
+/// Knapsack Solver Algorithm
+type KnapsackSolverAlgorithm =
+  | BruteForce
+  | SixtyFourItems
+  | DynamicProgramming
+  | MultidimensionCBC
+  | MultidimensionGLPK
+  | MultidimensionBranchAndBound
+  | MultidimensionSCIP
+  /// Solver Id
+  member this.Id =
+    match this with
+    | BruteForce -> 0
+    | SixtyFourItems -> 1
+    | DynamicProgramming -> 2
+    | MultidimensionCBC -> 3
+    | MultidimensionGLPK -> 4
+    | MultidimensionBranchAndBound -> 5
+    | MultidimensionSCIP -> 6
+
+let knapsackSolve (name: string) (solverAlgorithm:KnapsackSolverAlgorithm) (profits:int64 list) (weights:int64 list) (capacities:int64 list) =
+  // extract the specific algorithm so its Id can be used to create solver
+  let algorithm =
+    match solverAlgorithm with
+    | MultidimensionBranchAndBound ->
+        MultidimensionBranchAndBound.Id
+    | BruteForce ->
+        BruteForce.Id
+    | SixtyFourItems ->
+        SixtyFourItems.Id
+    | DynamicProgramming ->
+        DynamicProgramming.Id
+    | MultidimensionCBC ->
+        MultidimensionCBC.Id
+    | MultidimensionGLPK ->
+        MultidimensionGLPK.Id
+    | MultidimensionSCIP ->
+        MultidimensionSCIP.Id
+
+  let solver = new KnapsackSolver(algorithm, name)
+
+  // transform lists to compatible structures for C++ Solver
+  let profits = new KInt64Vector( List.toArray profits )
+
+  let weights =
+    let tempVector = new KInt64VectorVector(1)
+    let tempWeights = new KInt64Vector(List.toArray weights)
+    tempVector.Add(tempWeights)
+    tempVector
+
+  let capacities = new KInt64Vector (List.toArray capacities)
+
+  solver.Init(profits, weights, capacities)
+  solver
 
 type SolverOpts = {
   /// Name of the solver