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;

const f = (s) => {
    const length = s.length;
    let max = 0;
    for (let i = 0; i < length ; i++) {
        for (let j = length-1; j >=0 ; j--) {
            if(s[i]==s[j]){
                let index = 0;
                let a=[];
                for(let m=i,n=j;s[m]==s[n]&&(n>=0&&m<length);m++,n--){
                    index++;
                    a.push(s[m])
                }
                if(index>max&&a.join("")==a.reverse().join("")){
                    max=index;
                }
            }
        }
    }
    return max;
};

void (async function () {
    while ((line = await readline())) {
        console.log(f(line));
    }
})();