Boolean Matrix Java

PROGRAM TO SOLVE BOOLEAN MATRIX QUESTION

class Main

{ 

    public static void modifyMatrix(int mat[][]){

                  

        // variables to check if there are any 1 

        // in first row and column

        boolean row_flag = false;

        boolean col_flag = false;

                  

        // updating the first row and col if 1

        // is encountered

        for (int i = 0; i < mat.length; i++ ){

                for (int j = 0; j < mat[0].length; j++){

                        if (i == 0 && mat[i][j] == 1)

                            row_flag = true;

                          

                        if (j == 0 && mat[i][j] == 1)

                            col_flag = true;

                          

                        if (mat[i][j] == 1){

                              

                            mat[0][j] = 1;

                            mat[i][0] = 1;

                        }

                          

                    }

                }

                  

        // Modify the input matrix mat[] using the 

        // first row and first column of Matrix mat

        for (int i = 1; i < mat.length; i ++){

                for (int j = 1; j < mat[0].length; j ++){

                          

                    if (mat[0][j] == 1 || mat[i][0] == 1){

                            mat[i][j] = 1;

                        }

                    }

                }

                  

        // modify first row if there was any 1

        if (row_flag == true){

            for (int i = 0; i < mat[0].length; i++){

                        mat[0][i] = 1;

                    }

                }

                  

        // modify first col if there was any 1

        if (col_flag == true){

            for (int i = 0; i < mat.length; i ++){

                        mat[i][0] = 1;

            }

        }

    }

              

    /* A utility function to print a 2D matrix */

    public static void printMatrix(int mat[][]){

        for (int i = 0; i < mat.length; i ++){

            for (int j = 0; j < mat[0].length; j ++){

                System.out.print( mat[i][j] );

            }

                System.out.println("");

        }

    }

              

    // Driver function to test the above function

    public static void main(String args[] ){

                  

        int mat[][] = {{1, 0, 0, 1},

                {0, 0, 1, 0},

                {0, 0, 0, 0}};

                  

        System.out.println("Input Matrix :");

        printMatrix(mat);

              

        modifyMatrix(mat);

              

        System.out.println("Matrix After Modification :");

        printMatrix(mat);

              

    }

}







OUTPUT

Input Matrix :
1001
0010
0000
Matrix After Modification :
1111
1111
1011

CREDITS: https://www.geeksforgeeks.org/a-boolean-matrix-question/