题解 | #最长回文子串#

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
    // 解题思路
    // 采用动态规划，
    // 记录结果maxSubLength,curSubLength
    let maxSubLength = 1;
    while ((str = await readline())) {
        let length = str.length;
        // 定义状态:dp[i][j]表示第i到j为回文
        const dp = Array.from({ length: length }, () =>
            Array(length).fill(false)
        );
        for (let i = 0; i < length; i++) {
            dp[i][i] = true;
        }
        // console.log(dp);

        for (let len = 2; len <= length; len++) {
            for (let i = 0; i <= length-len; i++) {
                let j=i+len-1;
                if(str[i]==str[j]&&(len==2||dp[i+1][j-1])){
                    dp[i][j]=true;
                    // console.log(`sub: ${str.slice(i,j+1)}`)
                    maxSubLength=len;
                }
            }
        }
        console.log(maxSubLength);
    }
})();