题解 | #找出字符串中第一个只出现一次的字符#

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
    while(line = await readline()){
        getLetter(line)
    }
}()
function getLetter(line){
    let str=-1
    for(let i =0;i<line.length;i++){
        let index =line.indexOf(line[i])
        let lastindex = line.lastIndexOf(line[i])
        if(index===lastindex){
            str=line[i]
            break
        }
    }
    console.log(str)
}