Move zero elements down#9568
Given a two-dimensional array of size n \times m, shift all zero elements in each column downwards, so that all zeros in each column are moved to the bottom of their column, while maintaining the order of the other (nonzero) elements.
The first line contains two integers and — the number of rows and columns, respectively.
The following lines each contain integers, representing the elements of the array.
Output the modified array after all zeros have been moved down in each column.
Example 1