nqueens.cc fixup

Author: Mizux

examples/cpp/nqueens.cc

@@ -29,6 +29,7 @@
 #include "ortools/base/logging.h"
 #include "ortools/base/map_util.h"
 #include "ortools/base/types.h"
+#include "ortools/constraint_solver/constraint_solver.h"
 #include "ortools/constraint_solver/constraint_solveri.h"
 
 ABSL_FLAG(bool, print, false, "If true, print one of the solution.");
@@ -39,7 +40,6 @@ ABSL_FLAG(
     int, size, 0,
     "Size of the problem. If equal to 0, will test several increasing sizes.");
 ABSL_FLAG(bool, use_symmetry, false, "Use Symmetry Breaking methods");
-ABSL_DECLARE_FLAG(bool, cp_disable_solve);
 
 static const int kNumSolutions[] = {
     1, 0, 0, 2, 10, 4, 40, 92, 352, 724, 2680, 14200, 73712, 365596, 2279184};