题解 | #进制转换#

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

    let map = new Map();
    for (let i = 0; i < 10; i++) {
        map.set(String(i), i);
    }
    map.set('A', 10).set('B', 11).set('C', 12).set('D', 13).set('E', 14).set('F', 15)
    while ((line = await readline())) {
        // 方法1:
        // console.log(eval(line))

        // 方法2:
        // console.log(Number(line,16))

        // 方法3:
        // console.log(parseInt(line, 16))

        // 方法4:
        // let str = line.substring(2, line.length)
        // let arr = str.toUpperCase().split('')
        // let result = 0
        // for(let i = 0; i < arr.length; i++){
        //     let tempNum = Math.pow(16, arr.length - i - 1)
        //     result += map.get(arr[i]) * tempNum
        // }

        // console.log(result)

        // 方法5:
        const len = line.length;
        let result = 0;
        for(let i = len - 1; i > 1; i--){
            result += map.get(line[i]) * 16 ** (len - 1 - i);
        }
        console.log(result)
    }
})();