Given a string of lowercase letters. Find minimum characters to be inserted in string so that it can become palindrome. We can change positions of characters in string.
Input : geeksforgeeks Output : 2 geeksforgeeks can be changed as: geeksroforskeeg geeksorfroskeeg and many more Input : aabbc Output : 0 aabbc can be changed as: abcba bacab
A palindromic string can have one odd character only when length of string is odd otherwise all characters occur even number of times. So, we have to find characters which occur odd times in a string.
The idea is to count occurrence of each character in a string. As palindromic string can have one character which occur odd times so number of insertion will be one less then count of characters which occur odd times. And if string is already palindrome, we do not need to add any character so result will be 0.
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- Minimum insertions to form a palindrome | DP-28
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