Stair-case Problem

staircase.js

process.stdin.resume();
process.stdin.setEncoding("ascii");
var input = "";
process.stdin.on("data", function (chunk) {
input += chunk;
});
process.stdin.on("end", function () {
// now we can read/parse input
    var n = parseInt(input, 10);
    var str = [];
    for(var i=0; i<n; i++){
        var col = n-i-1;
        for(var j=0; j<n; j++){
            if (j>=col){
              str.push('#');    
            }else{
              str.push(' ');
            }
        }
        str.push('\n');
    }
    process.stdout.write(str.join(''));
});