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Author: Amrutansu Garanaik , Abhishek Patnaik
Tester: Keshow Sablaka, Amit Das
Editorialist: Amrutansu Garanaik , Amit Kumar Sahu

Difficulty :



Levenshtein distance algorithm, Longest common subsequence

Problem :

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


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.
This question is marked "community wiki".

asked 03 Apr '15, 20:15

dragonemperor's gravatar image

accept rate: 10%

All you need is a bit of maturity to generalise :) obviously you can never imagine in 4 th dimension !! Nice :)


answered 03 Apr '15, 23:32

anh1l1ator's gravatar image

accept rate: 11%

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question asked: 03 Apr '15, 20:15

question was seen: 971 times

last updated: 03 Apr '15, 23:32