125. 验证回文串

原题

https://leetcode.cn/problems/valid-palindrome/description/

思路

字符串处理

复杂度

时间：O(n)
空间：O(n)

Python代码

class Solution:
    def isPalindrome(self, s: str) -> bool:
        p = ''
        for ch in s:
            if ch.isalpha() or ch.isdigit():
                p += ch.lower()
        return p == p[::-1]
        

Go代码

func isPalindrome(s string) bool {
    var p string 
    for _, ch := range s {
        if ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') || ('0' <= ch && ch <= '9') {
            p += strings.ToLower(string(ch))
        }
    }
    var r string 
    for _, ch := range p {
        r = string(ch) + r
    }
    return p == r
}