题解 | 数字颠倒

const readline = require('readline');

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function (line) {
    const length = line.length;
    let index = 0
    const arr = []
    while(index < length) {
        let swapIndex = length-1-index
        arr[swapIndex] = line[index]
        index++
    }
    console.log(arr.join(''))
});