apolopena

// not written by me, I just put it here to try to understand the question, lol
function plusMinus(arr) {
  let pos = 0, neg = 0 , zero = 0 , length = arr.length
  arr.forEach( n => {
      if( n > 0 )
          pos++
      else if( n < 0 )
          neg++
      else
          zero++

apolopena

function staircase(n) {
 for (let i = 1; i <= n; i++) {
     console.log("#".repeat(i).padStart(n));
 }    
}

apolopena

function staircase(n) {
  let stairs = [];
  for (let i = 0; i < n; i++) {
    stairs.push(new Array(n).fill(' ')); // build a square 2d array (N high by N wide)
  }
  stairs.forEach((row, rIndex) => {
    row[rIndex] = '#'; // set the markers for the steps (#) left justified 
    row.reverse(); // reverse the array to make the staircase right justified
    // now edit the characters in the 2d array so they properly represent the staircase
    if(rIndex === 0) { // first row is always correct so do nothing

apolopena

function miniMaxSum(arr) {
    let minArr, maxArr;
    minArr = [...arr];
    maxArr = [...arr];
    let sumArray = function (arr) {
        return arr.reduce((sum, num) => { return sum += num; });
    }
    minArr.splice(minArr.indexOf(Math.max(...minArr)), 1);
    maxArr.splice(maxArr.indexOf(Math.min(...minArr)), 1);
    console.log(`${sumArray(minArr)} ${sumArray(maxArr)}`);

apolopena

// a two liner using Array.filter
function birthdayCakeCandles(ar) {
    const tallest = Math.max(...ar); 
    return ar.filter(candle => candle === tallest).length;
}
// or a 5-liner using a for loop
function birthdayCakeCandlesFor(ar) {
    const tallest = Math.max(...ar);
    let count = 0;
    for (let i = 0; i < ar.length; i++) {

apolopena

// NOTE: time string must look like this 07:05:45PM or this 07:05:45AM and account for 12:00:00AM and convert 12:00:00pm to 12:00:00
function timeConversion(s) {
    const ampm = s.slice(-2);
    const hours = Number(s.slice(0, 2));
    let time = s.slice(0, -2);
    if (ampm === 'AM') {
        if (hours === 12) { // 12am edge-case
            return  time.replace(s.slice(0, 2), '00');
        }
        return time;

apolopena

// my solution
function gradingStudents(grades) {
    return grades.map((grade, i) => {
        if (grade >= 38) {
            let r = grade % 5;
            if (r === 0 || r < 3) {
                return grade;
            }
            return grade + 5 - (grade % 5);
        }

apolopena

// my solution using easy to refactor methods (in case you wanted to either share logic or compare new types of fruit)
function countApplesAndOranges(s, t, a, b, apples, oranges) {
    const fLoc = function (treeLoc, arr2d) {
       return arr2d.map(fruitLoc => (treeLoc + fruitLoc));
    }
    const fRange = function (s, t, arr2d) {
        let a, b;
        a = 0; b = 0;
        arr2d.forEach((f, i) => {
            if (i === 0) { // apple count

apolopena

function fib(n, isSeq) {
    let seq = [];
    let Fn = 0, i = 2;
    let Fn_1 = 1, Fn_2 = 1;
    while( i < n) {
        Fn = Fn_1 + Fn_2; // Fibonacci rule Fn = F(n - 1) + F(n - 2);
        var prevFn_1 = Fn_1;
        Fn_1 = Fn;
        Fn_2 = prevFn_1;
        seq.push(Fn);

apolopena

function phi(n) { // do not surpass n >= 79 due to JavaScript's 32 bit integer limitation regarding decimal precision
    let ratios = [1, 1, 2], i = 2;
    let fs = fib(n, true);
    while (i < n - 1) {
        ratios.push((fs[i + 1] / fs[i]).toFixed(3));
        i++;
    }
    return ratios;
}
function fib(n, isSeq) {// accuracy is lost after n > 79