generate permutations of string

gistfile1.txt

process.stdin.resume();
process.stdin.setEncoding('ascii');

var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;

process.stdin.on('data', function (data) {
    input_stdin += data;
});

process.stdin.on('end', function () {
    input_stdin_array = input_stdin.split("\n");
    main();    
});

function readLine() {
    return input_stdin_array[input_currentline++];
}

/////////////// ignore above this line ////////////////////

function main() {
    var t = parseInt(readLine());
    for(var a0 = 0; a0 < t; a0++){
        var n = parseInt(readLine());
        console.log(findDecentNumber(n));
    }
}

function findDecentNumber(numDigits) {
    if (numDigits === 1) {
      return -1;
    }
    var incremend = 3;
    var highestDecentNumber = -1;
    var possibleDecentNumbers = generatePossibleDecentNumbers(numDigits);
    return possibleDecentNumbers.reduce(function (highest, current) {
        return highest > current ? highest : current;
    });
}

function generatePossibleDecentNumbers(numDigits) {
    'use strict';
    let possibilities = [''];
    for (let i = 0; i < numDigits; i++) {
        let newPossibilities = [];
        for (let j = 0; j < possibilities.length; j++) {
            newPossibilities = newPossibilities.concat(addNextDigit(possibilities[j]));
        }
        possibilities = newPossibilities;
    }
    
    return possibilities.filter(isDecentNumber);
}

function addNextDigit(curString) {
    return [parseInt(curString + '3'), parseInt(curString + '5')];
}

function isDecentNumber(num) {
    if (('' + num).match(/[^35]/)) {
        return false;
    }
    var stringifiedNum = '' + num;
    var matchesWithThree = stringifiedNum.match(/3/g) || [3,3,3,3,3];
    var matchesWithFive = stringifiedNum.match(/5/g) || [5,5,5];
    return matchesWithFive.length % 3 === 0 && matchesWithThree.length % 5 === 0;
}