727. 菱形

这js是真的难写啊!!!!!!
https://www.acwing.com/problem/content/729/

let fs = require('fs');
let buf = '';

process.stdin.on('readable', function() {
    let chunk = process.stdin.read();
    if (chunk) buf += chunk.toString();
});

process.stdin.on('end', function() {
    buf=parseInt(buf);
    let star=1;
    let space=parseInt(buf/2);
    let ans="";
    for(let i=0;i<buf;i++)
    {
        for(let j=0;j<space;j++)ans+=" ";
        for(let j=0;j<star;j++)ans+="*";
        if(i!=buf-1)ans+="\n";
        if(i<parseInt(buf/2))space--,star+=2;
        else space++,star-=2;
    }
    console.log(ans);
});