From e129e2da77af489c47f39cbb82d58fb203bf82ff Mon Sep 17 00:00:00 2001
From: Laurent Perron <lperron@google.com>
Date: Wed, 6 Jun 2018 14:32:29 +0200
Subject: [PATCH] fix examples

---
 examples/cpp/sat_runner.cc          |   2 +-
 examples/csharp/code_samples_sat.cs | 100 ++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+), 1 deletion(-)

diff --git a/examples/cpp/sat_runner.cc b/examples/cpp/sat_runner.cc
index e418941b53..a7cfed9ee5 100644
--- a/examples/cpp/sat_runner.cc
+++ b/examples/cpp/sat_runner.cc
@@ -33,7 +33,7 @@
 #include "ortools/sat/boolean_problem.pb.h"
 #include "ortools/sat/cp_model.pb.h"
 #include "ortools/sat/cp_model_solver.h"
-#include "ortools/sat/drat.h"
+#include "ortools/sat/drat_proof_handler.h"
 #include "ortools/sat/lp_utils.h"
 #include "ortools/sat/model.h"
 #include "examples/cpp/opb_reader.h"
diff --git a/examples/csharp/code_samples_sat.cs b/examples/csharp/code_samples_sat.cs
index 8b1038d62e..9876586e2f 100644
--- a/examples/csharp/code_samples_sat.cs
+++ b/examples/csharp/code_samples_sat.cs
@@ -145,6 +145,104 @@ public class CodeSamplesSat
     }
   }
 
+  static void BinpackingProblem()
+  {
+    // Data.
+    int bin_capacity = 100;
+    int slack_capacity = 20;
+    int num_bins = 10;
+
+    int[,] items = new int[,] { {20, 12}, {15, 12}, {30, 8}, {45, 5} };
+    int num_items = items.GetLength(0);
+
+    // Model.
+    CpModel model = new CpModel();
+
+    // Main variables.
+    IntVar[,] x = new IntVar[num_items, num_bins];
+    for (int i = 0; i < num_items; ++i)
+    {
+      int num_copies = items[i, 1];
+      for (int b = 0; b < num_bins; ++b)
+      {
+        x[i, b] = model.NewIntVar(0, num_copies, String.Format("x_{0}_{1}", i, b));
+      }
+    }
+
+    // Load variables.
+    IntVar[] loads = new IntVar[num_bins];
+    for (int b = 0; b < num_bins; ++b)
+    {
+      loads[b] = model.NewIntVar(0, bin_capacity, String.Format("load_{0}", b));
+    }
+
+    // Slack variables.
+    IntVar[] slacks = new IntVar[num_bins];
+    for (int b = 0; b < num_bins; ++b)
+    {
+      slacks[b] = model.NewBoolVar(String.Format("slack_{0}", b));
+    }
+
+    // Links load and x.
+    int[] sizes = new int[num_items];
+    for (int i = 0; i < num_items; ++i) {
+      sizes[i] = items[i, 0];
+    }
+    for (int b = 0; b < num_bins; ++b)
+    {
+      IntVar[] tmp = new IntVar[num_items];
+      for (int i = 0; i < num_items; ++i)
+      {
+        tmp[i] = x[i, b];
+      }
+      model.Add(loads[b] == tmp.ScalProd(sizes));
+    }
+
+    // Place all items.
+    for (int i = 0; i < num_items; ++i)
+    {
+      IntVar[] tmp = new IntVar[num_bins];
+      for (int b = 0; b < num_bins; ++b)
+      {
+        tmp[b] = x[i, b];
+      }
+      model.Add(tmp.Sum() == items[i, 1]);
+    }
+
+    // Links load and slack.
+    int safe_capacity = bin_capacity - slack_capacity;
+    for (int b = 0; b < num_bins; ++b)
+    {
+      //  slack[b] => loads[b] <= safe_capacity.
+      model.Add(loads[b] <= safe_capacity).OnlyEnforceIf(slacks[b]);
+      // not(slack[b]) => loads[b] > safe_capacity.
+      model.Add(loads[b] > safe_capacity).OnlyEnforceIf(slacks[b].Not());
+    }
+
+    // Maximize sum of slacks.
+    model.Maximize(slacks.Sum());
+
+    // Solves and prints out the solution.
+    CpSolver solver = new CpSolver();
+    CpSolverStatus status = solver.Solve(model);
+    Console.WriteLine(String.Format("Solve status: {0}", status));
+    if (status == CpSolverStatus.Optimal) {
+      Console.WriteLine(String.Format("Optimal objective value: {0}", solver.ObjectiveValue));
+      for (int b = 0; b < num_bins; ++b)
+      {
+        Console.WriteLine(String.Format("load_{0} = {1}", b, solver.Value(loads[b])));
+        for (int i = 0; i < num_items; ++i)
+        {
+          Console.WriteLine(string.Format("  item_{0}_{1} = {2}", i, b, solver.Value(x[i, b])));
+        }
+      }
+    }
+    Console.WriteLine("Statistics");
+    Console.WriteLine(String.Format("  - conflicts : {0}", solver.NumConflicts()));
+    Console.WriteLine(String.Format("  - branches  : {0}", solver.NumBranches()));
+    Console.WriteLine(String.Format("  - wall time : {0} s", solver.WallTime()));
+  }
+
   static void IntervalSample()
   {
     CpModel model = new CpModel();
@@ -269,6 +367,8 @@ public class CodeSamplesSat
     ReifiedSample();
     Console.WriteLine("--- RabbitsAndPheasants ---");
     RabbitsAndPheasants();
+    Console.WriteLine("--- BinpackingProblem ---");
+    BinpackingProblem();
     Console.WriteLine("--- IntervalSample ---");
     IntervalSample();
     Console.WriteLine("--- MinimalCpSat ---");