How to get the the sum of the right diagonal of the Matrix?-CodePudding

In this question, we asked you how to get the sum of the right diagonal of the Matrix.

For Example: we have a 3x3 Matrix:-
1 2 3
4 5 6
7 8 9

Sum of the Right is 15. How to do this in java code.

public static void main(String[] args) {
    int[][] array = {
            {1,2,3,10},
            {3,4,5,10},
            {7,5,9,5},
            {5,8,9,5}
    };

CodePudding user response：

You need to go thtow all rows and sum one number from each row. From the end of the row.

int i= array.length-1;
int sum=0;
for (int j = 0; j < i; j  ) {
    sum =array[j][i-j];
}

CodePudding user response：

You can do it like this

int[][] array = {
        {1,2,3,10},
        {3,4,5,10},
        {7,5,9,5},
        {5,8,9,5}
};
System.out.println(sumRightDiagonal(array));

prints

Get the right most column of the first row.
initialize the sum to 0
iterate over the rows of the matrix.
add current column of row to sum and decrement column
return the sum when done.

public static int sumRightDiagonal(int[][] mat) {
    
    int sum = 0;
    int col = mat[0].length-1;
    for (int[] row : mat) {
        sum  = row[col--];
    }
    return sum;
}