Watch 10 video solutions for Minimum Number of Moves to Make Palindrome, a hard level problem involving Two Pointers, String, Greedy. This walkthrough by Ashish Pratap Singh has 1,002,224 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
You are given a string s consisting only of lowercase English letters.
In one move, you can select any two adjacent characters of s and swap them.
Return the minimum number of moves needed to make s a palindrome.
Note that the input will be generated such that s can always be converted to a palindrome.
Example 1:
Input: s = "aabb" Output: 2 Explanation: We can obtain two palindromes from s, "abba" and "baab". - We can obtain "abba" from s in 2 moves: "aabb" -> "abab" -> "abba". - We can obtain "baab" from s in 2 moves: "aabb" -> "abab" -> "baab". Thus, the minimum number of moves needed to make s a palindrome is 2.
Example 2:
Input: s = "letelt" Output: 2 Explanation: One of the palindromes we can obtain from s in 2 moves is "lettel". One of the ways we can obtain it is "letelt" -> "letetl" -> "lettel". Other palindromes such as "tleelt" can also be obtained in 2 moves. It can be shown that it is not possible to obtain a palindrome in less than 2 moves.
Constraints:
1 <= s.length <= 2000s consists only of lowercase English letters.s can be converted to a palindrome using a finite number of moves.