Remove hard-coded symbols and magic numbers

TicTacToe/backend/TicTacToe.h

@@ -21,6 +21,6 @@ class TicTacToe {
     std::unique_ptr<TicTacToeBoard> board;
     int turn;
     Player players[2] = {HUMAN, COMPUTER};
-    static constexpr char symbols[2] = {'x', 'o'};
+    static constexpr char symbols[2] = {P1_SQUARE, P2_SQUARE};
 };
 #endif //GAMES_TICTACTOE_H

TicTacToe/backend/TicTacToeBoard.cpp

@@ -11,7 +11,7 @@ const TicTacToeBoard TicTacToeBoard::makeMove(const TicTacToeMove& m) const {
 
 inline
 bool TicTacToeBoard::isLegal(const TicTacToeMove &m) const {
-    if (d[m.i] != '.')
+    if (d[m.i] != EMPTY_SQUARE)
         return false;
     return true;
 }
@@ -20,7 +20,7 @@ GameState TicTacToeBoard::getGameState() const {
     auto str = d.getDescription();
     for (auto i = 0; i < BOARD_SIZE / 3; ++i) {
         auto state = checkLine(str[3 * i], str[3 * i + 1], str[3 * i + 2]);
-        if (state == 0) {
+        if (state == CONTINUE_STATE) {
             if (i == 0) {
                 state = checkLine(str[0], str[4], str[8]);
             } else {
@@ -29,37 +29,37 @@ GameState TicTacToeBoard::getGameState() const {
                 }
             }
         }
-        if (state == 1)
+        if (state == P1_WIN_STATE)
             return Win1;
-        else if (state == -1)
+        else if (state == P2_WIN_STATE)
             return Win2;
     }
     for (auto i = 0; i < BOARD_SIZE / 3; ++i) {
         auto state = checkLine(str[i], str[i + 3], str[i + 6]);
-        if (state == 1)
+        if (state == P1_WIN_STATE)
             return Win1;
-        else if (state == -1)
+        else if (state == P2_WIN_STATE)
             return Win2;
     }
-    if (numOccupied() < 9)
+    if (numOccupied() < BOARD_SIZE)
         return Continue;
     return Draw;
 }
 
 int TicTacToeBoard::numOccupied() const  {
     auto occ = 0;
     for (auto c: d.getDescription())
-        occ += (c != '.') ? 1 : 0;
+        occ += (c != EMPTY_SQUARE) ? 1 : 0;
     return occ;
 }
 
 int TicTacToeBoard::checkLine(char x, char y, char z) const {
-    if (x == y && y == z && x == 'x')
-        return 1;
+    if (x == P1_SQUARE && x == y && y == z)
+        return P1_WIN_STATE;
     else{
-        if (x == y && y == z && x == 'o')
-            return -1;
+        if (x == P2_SQUARE && x == y && y == z)
+            return P2_WIN_STATE;
         else
-            return 0;
+            return CONTINUE_STATE;
     }
-}
+}

TicTacToe/backend/TicTacToeBoard.h

@@ -5,6 +5,11 @@
 #include <stdexcept>
 #include <string>
 
+const int P1_WIN_STATE = 1;
+const int P2_WIN_STATE = -1;
+const int CONTINUE_STATE = 0;
+
+
 class TicTacToeMove {
 public:
     TicTacToeMove(int row, int col, char symbol) :r(row), c(col), s(symbol), i(3 * r + c) {

TicTacToe/backend/TicTacToeBoardDescriptor.cpp

@@ -7,7 +7,7 @@ TicTacToeBoardDescriptor::TicTacToeBoardDescriptor(const std::string d) :descrip
         throw std::invalid_argument("Length of descriptor " + d + " is invalid!");
 
     for (auto c: d){
-        if (c != '.' && c != 'o' && c != 'x')
+        if (c != EMPTY_SQUARE && c != P2_SQUARE && c != P1_SQUARE)
             throw std::invalid_argument("Found invalid character in descriptor!");
     }
 }
@@ -16,4 +16,4 @@ const TicTacToeBoardDescriptor TicTacToeBoardDescriptor::editDescription(int pos
     std::string newDescription(descriptor);
     newDescription[pos] = val;
     return TicTacToeBoardDescriptor(newDescription);
-}
+}

TicTacToe/backend/TicTacToeBoardDescriptor.h

@@ -4,6 +4,9 @@
 #include <string>
 
 const int BOARD_SIZE = 9;
+const char P1_SQUARE = 'x';
+const char P2_SQUARE = 'o';
+const char EMPTY_SQUARE = '.';
 
 class TicTacToeBoardDescriptor {
 public:

TicTacToe/engine/TicTacToePlayer.cpp

@@ -6,7 +6,7 @@
 TicTacToeMove TicTacToePlayer::generateMove(const TicTacToeBoardDescriptor& board, char next_sym, std::vector<int>& generated){
     auto last = generated.size() > 0 ? generated.back() : -1;
     for (auto i = ++last; i < BOARD_SIZE; ++i){
-        if (board[i] == '.'){
+        if (board[i] == EMPTY_SQUARE){
             generated.push_back(i);
             return TicTacToeMove(i, next_sym);
         }
@@ -59,7 +59,7 @@ int findMoveInTree(Tree& t) {
 
 TicTacToeMove TicTacToePlayer::play(const TicTacToeBoard & board) {
     Tree playTree(board.getDescriptor());
-    makeTree(playTree, assigned_simbol == 'x');
+    makeTree(playTree, assigned_simbol == P1_SQUARE);
     bool is_first = board.numOccupied() == 0;
     auto move = treeSearch(playTree, assigned_simbol, is_first);
     return move;
@@ -83,7 +83,7 @@ Tree& TicTacToePlayer::makeTree(Tree & t, bool x) {
     }
     while(1){
         try {
-            auto move = generateMove(b.getDescriptor(), x ? 'x' : 'o', generatedMoves);
+            auto move = generateMove(b.getDescriptor(), x ? P1_SQUARE : P2_SQUARE, generatedMoves);
             t.addChildren(new Tree(d.editDescription(move.i, move.s)));
         } catch (int e){ // Moves are finished
             break;
@@ -94,4 +94,4 @@ Tree& TicTacToePlayer::makeTree(Tree & t, bool x) {
         makeTree(t.getChildren(i), !x);
     }
     return t;
-}
+}

TicTacToe/engine/TicTacToePlayer.h

@@ -32,7 +32,7 @@ class Tree {
 class TicTacToePlayer {
 public:
     TicTacToePlayer(char symbol) :assigned_simbol(symbol) {
-        if (symbol != 'x' && symbol != 'o')
+        if (symbol != P1_SQUARE && symbol != P2_SQUARE)
             throw std::invalid_argument("Not a valid symbol!");
     };
     TicTacToeMove play(const TicTacToeBoard&);