Question

I have a 2-dimensional array where I need to convert the first diagonal numbers to zero. For example, I need to convert the following:

[ 1 2 3 ]
[ 5 9 5 ]
[ 3 2 1 ]

To this, meaning the diagonal 1 9 1 is now 0 0 0:

[ 0 2 3 ]
[ 5 0 5 ]
[ 3 2 0 ]

How can I efficiently do this in C#?

Answer 1

All you’re doing is setting the points in the grid to be zero when X and Y are equal. (1,1), (2,2), and so on;

int x = 4, y = 5;
int[,] array = new int[x,y]; // assume we initialize this with some values
for (int i = 0; i < x && i < y; i++ ) {
    array[i,i] = 0;
}