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$ curl repovive.com/roadmaps/meta-interview-prep-v2/coding-patterns-i-arrays-strings-stacks/lc-680-valid-palindrome-ii-implementation

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$ curl repovive.com/roadmaps/meta-interview-prep-v2/coding-patterns-i-arrays-strings-stacks/lc-680-valid-palindrome-ii-implementation

Repovive

LeetCode 680 Valid Palindrome II - Implementation - Coding Patterns I: Arrays, Strings & Stacks | Meta Interview Prep | Repovive

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Meta Interview Prep6 sections · 147 units8h total

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LeetCode 680 Valid Palindrome II - Implementation

The code

Check if the string is a palindrome with one allowed deletion. When a mismatch occurs, try removing either side.

Here's the solution:

function validPalindrome(s):
    left = 0
    right = s.length - 1
    while left < right:
        if s[left] != s[right]:
            return isPalin(s, left+1, right) or isPalin(s, left, right-1)
        left += 1
        right -= 1
    return true

function isPalin(s, lo, hi):
    while lo < hi:
        if s[lo] != s[hi]:
            return false
        lo += 1
        hi -= 1
    return true

$O(n)$ time, $O(1)$ space.