## Problem Link :

**Author:** Amrutansu Garanaik , Abhishek Patnaik

**Tester:** Keshow Sablaka, Amit Das

**Editorialist:** Amrutansu Garanaik , Amit Kumar Sahu

## Difficulty :

Easy-medium

# Pre-requisite Levenshtein distance algorithm, Longest common subsequence

## Problem :

Given four strings, find minimum number of charater removal required to make all the

strings equal.

## Explanation

### Approach 1

The problem is a standard dynamic programming problem. This can be solved using

Levenshtein distance algorithm, also known as Edit distance algorithm. For the given problem, we

had to extend the algorithm for four strings. See the setter solution 1 for implementation.

### Approach 2

Since we are to make the strings equal only by removing certain elements, the resulting

strings must be equal to the longest common subsequence of the strings. So, finding the length of

the longest common subsequence is required which is also a standard dynamic programming

problem. After finding the length of the longest common subsequence, we can subtract it from the

lengths of the each strings. The difference is the number of characters removed from the string. The

sum of the results of the four subtractions is the required number of characters removed.

See the setter solution 2 for implementation.

*N.B. If you can solve it using some other methods, please share in the comments.*