fix examples after FEASIBLE -> OPTIMAL CP-SAT change; improve display of the sudoku problem

examples/cpp/costas_array_sat.cc

@@ -185,7 +185,7 @@ void CostasBool(const int dim) {
   }
   const CpSolverResponse response = SolveCpModel(cp_model.Build(), &model);
 
-  if (response.status() == CpSolverStatus::FEASIBLE) {
+  if (response.status() == CpSolverStatus::OPTIMAL) {
     std::vector<int64> costas_matrix;
     std::string output;
 

examples/cpp/magic_square_sat.cc

@@ -74,8 +74,8 @@ void MagicSquare(int size) {
 
   const CpSolverResponse response = SolveCpModel(builder.Build(), &model);
 
-  if (response.status() == CpSolverStatus::FEASIBLE) {
-    for (int n = 0; n < size; ++n) {
+  if (response.status() == CpSolverStatus::OPTIMAL) {
+    for (int n = 0; n < size; ++n) {  
       std::string output;
       for (int m = 0; m < size; ++m) {
         absl::StrAppendFormat(&output, "%3d ",

examples/python/cover_rectangle_sat.py

@@ -85,7 +85,7 @@ def cover_rectangle(num_squares):
     print('%s found in %0.2fs' % (solver.StatusName(status), solver.WallTime()))
 
     # Prints solution.
-    if status == cp_model.FEASIBLE:
+    if status == cp_model.OPTIMAL:
         display = [[' ' for _ in range(size_x)] for _ in range(size_y)]
         for i in range(num_squares):
             sol_x = solver.Value(x_starts[i])

examples/python/hidato_sat.py

@@ -161,7 +161,7 @@ def solve_hidato(puzzle, index):
     solver = cp_model.CpSolver()
     status = solver.Solve(model)
 
-    if status == cp_model.FEASIBLE:
+    if status == cp_model.OPTIMAL:
         if visualization.RunFromIPython():
             output = visualization.SvgWrapper(10, r, 40.0)
             for i, var in enumerate(positions):

examples/python/sudoku_sat.py

@@ -66,9 +66,16 @@ def solve_sudoku():
     # Solve and print out the solution.
     solver = cp_model.CpSolver()
     status = solver.Solve(model)
-    if status == cp_model.FEASIBLE:
+    if status == cp_model.OPTIMAL:
         for i in line:
-            print([int(solver.Value(grid[(i, j)])) for j in line])
+            output = ''
+            for j in line:
+                output += str(int(solver.Value(grid[(i, j)]))) + ' '
+                if j == 2 or j == 5:
+                    output += '| '
+            print(output)
+            if i == 2 or i == 5:
+                print('------|-------|-------')
 
 
 solve_sudoku()

examples/python/zebra_sat.py

@@ -110,7 +110,7 @@ def solve_zebra():
     solver = cp_model.CpSolver()
     status = solver.Solve(model)
 
-    if status == cp_model.FEASIBLE:
+    if status == cp_model.OPTIMAL:
         people = [englishman, spaniard, japanese, ukrainian, norwegian]
         water_drinker = [
             p for p in people if solver.Value(p) == solver.Value(water)