Two Pointers - Minimum Length of String After Deleting Similar Ends

Delete matching characters from both ends (same char prefix from left, suffix from right). Minimize length.

Input: s="ca" → Output: 2

Input: s="cabaabac" → Output: 0

Input: s="aabccabba" → Output: 3

Two pointers: while left < right and chars match, delete all matching chars on both sides.

left=0, right=n-1
While left < right and s[left]==s[right]
Advance left past all s[left] chars
Advance right back past all s[right] chars
Return max(0, right-left+1)

public int minimumLength(String s) { int left = 0, right = s.length() - 1; while (left < right && s.charAt(left) == s.charAt(right)) { char c = s.charAt(left); while (left <= right && s.charAt(left) == c) left++; while (left <= right && s.charAt(right) == c) right--; } return right - left + 1; }

Time Complexity: O(n)
Space Complexity: O(1)