Creating matrix with getting maximum of each row and column

Question

I want to make the minimum matrix given the max of each row and column.

Example:

Given:

row_max = [50, 20]
col_max = [50, 20, 3]

Result:

array = [[50, 0, 0],
         [0, 20, 3]]

Answer 1

Let maxColIndex be column's index which contains maximum value within col_max:

col_max = [50, 20, 3] # maxColIndex = 0

Let maxRowIndex be row's index which contains maximum value within row_max:

row_max = [10, 50, 20, 5] # maxRowIndex = 1

So we have

    | 50 20  3 
 ------------- 
 10 |  ?  ?  ? 
 50 |  ?  ?  ? <- maxRowIndex 
 20 |  ?  ?  ?
  5 |  ?  ?  ?
       ^
  maxColIndex

Now our goal is to put as many 0 as possible. Please note, that if there are same values in both max and min rows collections (e.g. 50, 20) we can put just one value:

    | 50 20  3 
 ------------- 
 10 |  ?  ?  ? 
 50 | 50  ?  ? <- maxRowIndex 
 20 |  ? 20  ?
  5 |  ?  ?  ?
       ^
  maxColIndex

Now put all the rest row_max values into the maxColIndex column:

    | 50 20  3 
 ------------- 
 10 | 10  ?  ? 
 50 | 50  ?  ? <- maxRowIndex 
 20 |  ? 20  ?
  5 |  5  ?  ?
       ^
  maxColIndex

Finally, put all the rest col_max values into the maxRowIndex row:

    | 50 20  3 
 ------------- 
 10 | 10  ?  ? 
 50 | 50  ?  3 <- maxRowIndex 
 20 |  ? 20  ?
  5 |  5  ?  ?
       ^
  maxColIndex

All indexes are set, time to fill the unset items of the matrix

    | 50 20  3 
 ------------- 
 10 | 10  0  0 
 50 | 50  0  3 <- maxRowIndex 
 20 |  0 20  0
  5 |  5  0  0
       ^
  maxColIndex