5. Given a boolean matrix mat[M][N] of size M X N, modify it such that if a matrix cell mat[i][j] is 1 (or true)

then make all the cells of ith row and jth column as 1.

6. Check if a sub-array exists in parent array.

Link: https://github.com/techpanja/interviewproblems/blob/master/src/arrays/findarray/FindArrayImpl.java