README_EN.md

comments	difficulty	edit_url	rating	source	tags
true	Easy	https://github.com/doocs/leetcode/edit/main/solution/2100-2199/2108.Find%20First%20Palindromic%20String%20in%20the%20Array/README_EN.md	1215	Weekly Contest 272 Q1	Array Two Pointers String

2108. Find First Palindromic String in the Array

中文文档

Description

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.

Solutions

Solution 1

Python3

class Solution:
    def firstPalindrome(self, words: List[str]) -> str:
        return next((w for w in words if w == w[::-1]), "")

Java

class Solution {
    public String firstPalindrome(String[] words) {
        for (var w : words) {
            boolean ok = true;
            for (int i = 0, j = w.length() - 1; i < j && ok; ++i, --j) {
                if (w.charAt(i) != w.charAt(j)) {
                    ok = false;
                }
            }
            if (ok) {
                return w;
            }
        }
        return "";
    }
}

C++

class Solution {
public:
    string firstPalindrome(vector<string>& words) {
        for (auto& w : words) {
            bool ok = true;
            for (int i = 0, j = w.size() - 1; i < j; ++i, --j) {
                if (w[i] != w[j]) {
                    ok = false;
                }
            }
            if (ok) {
                return w;
            }
        }
        return "";
    }
};

Go

func firstPalindrome(words []string) string {
	for _, w := range words {
		ok := true
		for i, j := 0, len(w)-1; i < j && ok; i, j = i+1, j-1 {
			if w[i] != w[j] {
				ok = false
			}
		}
		if ok {
			return w
		}
	}
	return ""
}

TypeScript

function firstPalindrome(words: string[]): string {
    for (const word of words) {
        let left = 0;
        let right = word.length - 1;
        while (left < right) {
            if (word[left] !== word[right]) {
                break;
            }
            left++;
            right--;
        }
        if (left >= right) {
            return word;
        }
    }
    return '';
}

Rust

impl Solution {
    pub fn first_palindrome(words: Vec<String>) -> String {
        for word in words.iter() {
            let s = word.as_bytes();
            let mut left = 0;
            let mut right = s.len() - 1;
            while left < right {
                if s[left] != s[right] {
                    break;
                }
                left += 1;
                right -= 1;
            }
            if left >= right {
                return word.clone();
            }
        }
        String::new()
    }
}

C

char* firstPalindrome(char** words, int wordsSize) {
    for (int i = 0; i < wordsSize; i++) {
        int left = 0;
        int right = strlen(words[i]) - 1;
        while (left < right) {
            if (words[i][left] != words[i][right]) {
                break;
            }
            left++;
            right--;
        }
        if (left >= right) {
            return words[i];
        }
    }
    return "";
}