What does the variable do to this function in C?-CodePudding

I recently asked for help on a code. However, I am confused of what does it do to my code. Anyways, this is already correct. I just want to know how does the parameters on this one work and their purpose, specifically af, bf, v and v2.

void validateMoveHelper(int x1, int y1, int af, int bf, int v, int v2) {
    for(int a = 1, b = 1; board[x1   af * a][y1   bf * b] == ' '; a  , b  ) {
        if((x1   af * a) == v || (y1   bf * b) == v2)
            return;
        printf("%d%d , ", x1   af * a , y1   bf * b);
    }
}

void validateMove(int x1, int y1) {
    printf( "Available coordinates to send the piece are: \n" ) ;
    validateMoveHelper(x1, y1, -1, -1,  1,  8);
    validateMoveHelper(x1, y1,  8,  1, -1, -1);
    validateMoveHelper(x1, y1,  8,  1,  1,  8);
    validateMoveHelper(x1, y1, -1, -1, -1, -1);
}

CodePudding user response：

The validateMoveHelper function is a helper function that is used by the validateMove function to determine the available coordinates to which a piece can be moved on a chessboard. The validateMoveHelper function takes the following parameters:

x1: The starting x-coordinate of the piece that is being moved.
y1: The starting y-coordinate of the piece that is being moved.
af: The amount to add to the x-coordinate for each step in the iteration. This parameter determines the direction in which the function will iterate over the chessboard.
bf: The amount to add to the y-coordinate for each step in the iteration. This parameter determines the direction in which the function will iterate over the chessboard.
v: The maximum or minimum value that the x-coordinate can have. This parameter determines when the iteration should stop.
v2: The maximum or minimum value that the y-coordinate can have. This parameter determines when the iteration should stop.

The validateMoveHelper function uses a for loop to iterate over the chessboard in the direction specified by the af and bf parameters. For each step in the iteration, the function checks if the current position on the chessboard is empty (i.e., if it contains a space character) and if the x-coordinate or y-coordinate has reached the maximum or minimum value specified by the v and v2 parameters. If either of these conditions is true, the function returns without printing any coordinates. Otherwise, it prints the current x-coordinate and y-coordinate.

The validateMove function uses the validateMoveHelper function to iterate over the chessboard in four different directions (top-left, top-right, bottom-left, bottom-right) to determine the available coordinates to which a piece can be moved. It does this by calling validateMoveHelper four times, passing in different values for the af, bf, v, and v2 parameters to specify the direction and boundaries of the iteration.

Overall, the validateMoveHelper and validateMove functions are used to determine the possible moves for a piece on a chessboard. The af and bf parameters determine the direction of the iteration, while the v and v2 parameters determine the boundaries of the iteration. These parameters enable the functions to handle a variety of different scenarios and move patterns on the chessboard.