LeetCode地址

最长回文子串

算法难度

中等

JS代码

/**
 * @param {string} s
 * @return {string}
 */
var longestPalindrome = function(s) {
    let left = 0
    let index = 0
    let right = 0
    let max = 0
    let start = 0
    let len = s.length

    while(index < len) {
        left = index - 1
        right = index

        while(s[right] === s[index]) {
            right++
        }

        index = right

        while(left >= 0 && right < len && s[right] === s[left]) {
            right++
            left--
        }

        if (right - left - 1 > max) {
            max = right - left - 1
            start = left + 1
        }

    }

    return s.substr(start, max)
};