It can be i=m-1 and j==n-1 because m-1 and n-1 are the last index of matrix and (m,n) will be outside of the matrix na?
And one more doubt is how we can be able to get this type of Logic on our own?
Why is it (i==m || j==n) as base case?
@gvspraveen113 see time stamp 15.20 m actually contains m-1 only as m-1 is passed from main (same for n)
you will be able to do these type of questions after going through some of these like this one sudoku solver n queen etc
dont forget to hit like and mark resolved if cleared 
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