Tic Tac Toe game

An easy to learn game for beginners. 
The game is written in C++ and illustrates proper structure for game development.

Author: aryansarkar13

tictactoe.cpp

@@ -0,0 +1,146 @@
+#include <iostream>
+using namespace std;
+
+//initialising array
+char square[10] = {'o','1','2','3','4','5','6','7','8','9'};
+
+int checkwin();
+void board();
+
+int main()
+{
+	int player = 1,i,choice;
+
+    char mark;
+    do
+    {
+        board();
+        player=(player%2)?1:2;
+
+        cout << "Player " << player << ", enter a number:  ";
+        cin >> choice;
+
+        mark=(player == 1) ? 'X' : 'O';
+
+        if (choice == 1 && square[1] == '1')
+
+            square[1] = mark;
+        else if (choice == 2 && square[2] == '2')
+
+            square[2] = mark;
+        else if (choice == 3 && square[3] == '3')
+
+            square[3] = mark;
+        else if (choice == 4 && square[4] == '4')
+
+            square[4] = mark;
+        else if (choice == 5 && square[5] == '5')
+
+            square[5] = mark;
+        else if (choice == 6 && square[6] == '6')
+
+            square[6] = mark;
+        else if (choice == 7 && square[7] == '7')
+
+            square[7] = mark;
+        else if (choice == 8 && square[8] == '8')
+
+            square[8] = mark;
+        else if (choice == 9 && square[9] == '9')
+
+            square[9] = mark;
+        else
+        {
+            cout<<"Invalid move ";
+
+            player--;
+            cin.ignore();
+            cin.get();
+        }
+        i=checkwin();
+
+        player++;
+    }while(i==-1);
+    board();
+    if(i==1)
+
+        cout<<"==>\aPlayer "<<--player<<" win ";
+    else
+        cout<<"==>\aGame draw";
+
+    cin.ignore();
+    cin.get();
+    return 0;
+}
+
+/*
+    FUNCTION TO RETURN GAME STATUS
+    1 FOR GAME IS OVER WITH RESULT
+    -1 FOR GAME IS IN PROGRESS
+    O GAME IS OVER AND NO RESULT
+*/
+
+int checkwin()
+{
+    if (square[1] == square[2] && square[2] == square[3])
+
+        return 1;
+    else if (square[4] == square[5] && square[5] == square[6])
+
+        return 1;
+    else if (square[7] == square[8] && square[8] == square[9])
+
+        return 1;
+    else if (square[1] == square[4] && square[4] == square[7])
+
+        return 1;
+    else if (square[2] == square[5] && square[5] == square[8])
+
+        return 1;
+    else if (square[3] == square[6] && square[6] == square[9])
+
+        return 1;
+    else if (square[1] == square[5] && square[5] == square[9])
+
+        return 1;
+    else if (square[3] == square[5] && square[5] == square[7])
+
+        return 1;
+    else if (square[1] != '1' && square[2] != '2' && square[3] != '3' 
+                    && square[4] != '4' && square[5] != '5' && square[6] != '6' 
+                  && square[7] != '7' && square[8] != '8' && square[9] != '9')
+
+        return 0;
+    else
+        return -1;
+}
+
+
+/*
+     FUNCTION TO DRAW BOARD OF TIC TAC TOE WITH PLAYERS MARK
+*/
+
+
+void board()
+{
+    system("cls");
+    cout << "\n\n\tTic Tac Toe\n\n";
+
+    cout << "Player 1 (X)  -  Player 2 (O)" << endl << endl;
+    cout << endl;
+
+    cout << "     |     |     " << endl;
+    cout << "  " << square[1] << "  |  " << square[2] << "  |  " << square[3] << endl;
+
+    cout << "_____|_____|_____" << endl;
+    cout << "     |     |     " << endl;
+
+    cout << "  " << square[4] << "  |  " << square[5] << "  |  " << square[6] << endl;
+
+    cout << "_____|_____|_____" << endl;
+    cout << "     |     |     " << endl;
+
+    cout << "  " << square[7] << "  |  " << square[8] << "  |  " << square[9] << endl;
+
+    cout << "     |     |     " << endl << endl;
+}