Lock in full 90-day FAANG roadmap access before Jan 14, 2026.
⌘K
Minimum Insertion Steps to Make a String Palindrome - Hard DSA Problem | Thita.ai
Minimum Insertion Steps to Make a String Palindrome
Difficulty: Hard
Category: DSA
Topics: Dynamic Programming
Asked at: Amazon, LinkedIn
Given a string `s`. In one step you can insert any character at any index of the string.
Return the minimum number of steps to make `s` palindrome.
A Palindrome String is one that reads the same backward as well as forward.
Example 1:
Input: s = "zzazz"
Output: 0
Explanation: The string "zzazz" is already palindrome we don't need any insertions.
Example 2:
Input: s = "mbadm"
Output: 2
Explanation: String can be "mbdadbm" or "mdbabdm".
Example 3:
Input: s = "leetcode"
Output: 5
Explanation: Inserting 5 characters the string becomes "leetcodocteel".
Example 4:
Input: s = "g"
Output: 0
Example 5:
Input: s = "no"
Output: 1
Constraints:
`1 <= s.length <= 500`
All characters of `s` are lower case English letters.