162-too-unique

Too unique

Challenge Description:

You are given a matrix of size N×M elements, filled with lowercase ASCII letters from ‘a’ to ‘z’. Find the max size of rectangular contiguous submatrix of unique (i.e. non repeated within a given submatrix) elements. Find all submatrices of unique elements of this size and replace their elements with asterisks ‘*’.

Input sample:

The first argument is a file that contains the input matrix. E.g.

rzqicaiiaege
ccwnulljybtu
jxtxupauwuah
oqikzgqrzpdq
vblalwdjbdwn
ahjeencuclbo

Output sample:

Print to stdout the result of the matrix with replaced elements, where all elements of the biggest submatrixes of unique elements are replaced with asterisks ‘*’. E.g.

rzqicaiiae**
ccwnulljyb**
jxtx***uwu**
oqik****zp**
vbla****bd**
ahje****cl**

Constraints:

1. The size of matrix in the input is 60×20 elements.