题解 | #取近似值#

const rl = require("readline").createInterface({input:process.stdin});
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

//方法一:借助parseInt
void async function(){
    const num = await readline();
    // console.log(num);
    if(num-parseInt(num)>=0.5) console.log(parseInt(num)+1);
    else console.log(parseInt(num));
}()
// 方法二：不使用任何内置方法
void async function(){
    const str = String(await readline());
    let res = 0,cur = "",flag = false,next = 0;
    for(const c of str){
        if(flag) {
            next = c - 0;
            break;
        }
        if(c === ".") {
            res = cur - 0;
            flag = true;
        }
        cur = cur + c;
    }
    res += next>=5?1:0;
    console.log(res);
}()