fix state representation not being updated when toggling restricted movement

include/klotski.hpp

@@ -272,6 +272,8 @@ public:
 
   auto ToggleTarget(int x, int y) -> bool;
 
+  auto ToggleRestricted() -> void;
+
   auto MoveBlockAt(int x, int y, Direction dir) -> bool;
 
   auto GetNextStates() const -> std::vector<State>;

src/klotski.cpp

@@ -162,6 +162,11 @@ auto State::ToggleTarget(int x, int y) -> bool {
   return true;
 }
 
+auto State::ToggleRestricted() -> void {
+  restricted = !restricted;
+  state.replace(0, 1, restricted ? "R" : "F");
+}
+
 auto State::MoveBlockAt(int x, int y, Direction dir) -> bool {
   Block block = GetBlock(x, y);
   if (!block.IsValid()) {

src/main.cpp

@@ -266,7 +266,7 @@ auto main(int argc, char *argv[]) -> int {
     } else if (IsKeyPressed(KEY_O)) {
       renderer.connect_solutions = !renderer.connect_solutions;
     } else if (IsKeyPressed(KEY_F)) {
-      current_state.restricted = !current_state.restricted;
+      current_state.ToggleRestricted();
       previous_state = clear_masssprings(masssprings, current_state);
       edited = true;
     } else if (IsKeyPressed(KEY_T)) {