Tic-Tac-Toe

The problem is described here:

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The Solution

My solution is a data structure named Tic_Matrix, its components is two arrays and two variables:

• array x for columns
• array y for rows
• diag1 for the first diagonal
• diag2 for the second diagonal

These variables are of type struct named Tic_Cell, its components:

• counter of type integer
• is_x is true when entries is X

When turn is taking place, lets say, put X on the cell at second column and third row:

turn(board, 'X', 2, 3);

If the 2^nd column not contain any entries, counter of the 2^nd variable in the array x will incremented and is_x will be true. Same thing happen to 3^rd row.
Turn after turn, whenever any counter reachs n (number of rows), the program check is_x of the variable that the counter belongs to, if it is true player X wins, if false player O wins.
If a play is made that O is putted in a column or a row have X, the counter of that column will be -1, to end of the game.

Same thing happen to the diagonals diag1 & diag2, but the trick here is to know if the current cell belongs to any diagonal.

At the first time, I tried to recognize a pattern where the cell does not belong to a diagonal, but this seemed go randomly especially when n is a large number.
After that I tried the opposite, so I recognized the pattern for the first diagonal - when row number = column number. The second diagonal had been more tricky. After a while, the other pattern came to my mind. If x is the column and y is the row, the cell belongs to the 2^nd diagonal when (n - x) = (y - 1).