2108. Find First Palindromic String in the Array

Problem Link

Description

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Given an array of strings words, return the first palindromic string in the array. If there is no such string, return an empty string "".

A string is palindromic if it reads the same forward and backward.

 

Example 1:

Input: words = ["abc","car","ada","racecar","cool"]
Output: "ada"
Explanation: The first string that is palindromic is "ada".
Note that "racecar" is also palindromic, but it is not the first.

Example 2:

Input: words = ["notapalindrome","racecar"]
Output: "racecar"
Explanation: The first and only string that is palindromic is "racecar".

Example 3:

Input: words = ["def","ghi"]
Output: ""
Explanation: There are no palindromic strings, so the empty string is returned.

 

Constraints:

• 1 <= words.length <= 100
• 1 <= words[i].length <= 100
• words[i] consists only of lowercase English letters.

Solution

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Python3

class Solution:
    def firstPalindrome(self, words: List[str]) -> str:
        def isPal(word):
            N = len(word)
            i, j = 0, N - 1
 
            while i <= j and word[i] == word[j]:
                i += 1
                j -= 1
            
            return i >= j
 
        for x in words:
            if isPal(x):
                return x
                
        return ""