题解 | 密码截取

const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

void (async function () {
    // Write your code here
    str = await readline();
    let arr = str.split("");
    let len = arr.length;
    let max = 0;
    for (let i = 0; i < len; i++) {
       let len1 = parlindrome(i,i+1)
       let len2 = parlindrome(i,i)
       max = Math.max(max,len1,len2)
    }
    console.log(max)

    function parlindrome(a, b) {
        while (a >= 0 && b < len && arr[a--] == arr[b++]) {
            if (b - a - 1 > max) {
                max = b - a - 1;
            }
        }
        return max
    }
})();