Question

This is due in a few hours I don't know if I did this correctly can you double check my code to see if my return statements are fine and I follow the instructions accurately. Thank you!!!

Modify my code if anything return statement seems misplaced or inaccurately called.

Here is my code:

int write_sudoku_board(const char file_name[ ], int board[9][9])
{
    int number;
    int i,j;
    int a = 9;
    FILE* fp  = fopen("sudoku.txt", "w");
    int count = 0;
    for(i = 0; i < a; i++){
        for(j = 0; j < 9; j++) {
            if (board[i][j] == 0)
                fprintf(fp, "-");

            else {
                fprintf(fp, "%d", board[i][j]);
            }

        }
        fprintf(fp,"\n");
        count++;
    }
    number = is_valid_board(board);
    if(number == 1)
        return 0;
    else if(count != a-1)
        return -1;
    else
        return -2;
}

int is_valid_board(int board[9][9]) {

    int array[10];
    int array_box[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
    int i, j, k, x, y; //rows=i, columns =j
    for (i=0; i<9; i++) {

//Reset test array
        for (x = 0; x < 10; x++) {
            array[x] = 0;
        }

//Checking for columns
        for (j=0; j<9; j++) {
            k = board[j][i];
            if (board[j][i] >= 0 && board[j][i]<= 9 && k != 0 && array[k]) { //ensuring values are between 1-9
                print_sudoku_board(board);
                return 0;
            }
            array[k]++;
        }

//Reset test array
        for (x = 0; x < 10; x++) {
            array[x] = 0;
        }

//Checking for columns
        for (j=0; j<9; j++) {
            k = board[i][j];
            if (board[i][j] >= 0 && board[j][i]<= 9 && k != 0 && array[k]) { //ensuring values are between 1-9
                print_sudoku_board(board);
                return 0;
            }
            array[k]++;
        }


    }

    for (i=0; i<3; i++) {
        for (j=0; j<3; j++) {
//Reseting array for box
            for (x = 0; x < 10; x++) {
                array_box[x] = 0;
            }

            for (x = i * 3; x < i * 3 + 3; x++) {
                for (y = j*3; y < j * 3 + 3; y++) {
                    k = board[x][y];
                    if (k != 0 && array_box[k]) {
                        print_sudoku_board(board);
                        return 0;
                    }
                    array_box[k]++;
                }
            }
        }
    }
    return 1;


}

13 Save Sudoku board to a file Implement a function with the following prototype: int write_sudoku_board(const char file_name[], int board[91[91); This function should save the board to a file. The function should return 0 on success, -1 if any file I/O error occurred and -2 if an invalid board was provided. In the output file, write a line for each row, with no spaces, and use a dash (the '-' character) to represent blanks. For example, the Sudoku board on page 1 should be saved as follows: 6-32-8-5 4--1 7 23---7-6 4--1 57--492 3--64 7 1 31-758--6 Hint: If you have read the board from the same file (using the function from Step 12), make sure you close the file and re-open it before saving the board. 3 Check board validity Implement a function that checks whether a board is valid: int is valid_board(int board[9][9]) The function should return 0 if the board parameter violates any of the Sudoku rules and board is valid. You have to check four constraints: fhe Each cell holds a number between 1-9 (for the filled cells) or 0 (for the blanks). . No umber is repeated in any row. . No number is repeated in any column . No number is repeated in any box

Answer 1

Your code seems fine to me . You have put all return statements at correct positions like if board is valid you are returning is 0 and if invqlid you are returning -2 . Also if there is any file input error then count wont be a-1 hence you are returning -1 which is according to conditions given in the question.

One thing i want to mention that you should close your file after all opeartions using fclose function as it is a good practice to close it.

Also you are passing correct errors in is_valid_board function by passing 0 for invalid board and 1 for valid board.