code golf cont'd

dynamic-arr-eval.js

const findInArray = (array, iterator) => {
    for (let [i, v] of Object.entries(array)) {
        if (iterator(v, Number(i))) {
            return Number(i);
        }
    }
  return -1;
};

/* 
  Prompt
  
  "We'll create a function that takes in two parameters:

  - a sequence (length and types of items are irrelevant)
  - a function (value, index) that will be called on members of the sequence and their index. 
    The function will return either true or false.
    
  Your function will iterate through the members of the sequence in order until the provided function returns true;
  at which point your function will return that item's index.

  If the function given returns false for all members of the sequence, your function should return -1."

*/

factorial.js

const factorial = n => n < 0 ? null : `${Array.from({ length: n }, (_, i) => i + 1).reduce((x, y) => x * y)}`;

fizz-buzz.js

const solution = n => {
    let a = 0,
        b = 0,
        c = 0;
    for (let i = 1; i < n; i++) {
      i % 3 === 0 ? i % 5 === 0 ? c++ : a++ : i % 5 === 0 ? b++ : "";
    }
    return [a, b, c];
};


/* 
  Prompt
  "Write a function that takes an integer and returns an array [A, B, C], 
  where A is the number of multiples of 3 (but not 5) below the given integer, 
  B is the number of multiples of 5 (but not 3) below the given integer 
  and C is the number of multiples of 3 and 5 below the given integer.

  For example, solution(20) should return [5, 2, 1]"

*/

max-multiple.js

const maxMultiple = (divisor, bound) => {
    for (let i = bound; i > 0; i--) {
        if (i % divisor === 0) {
            return i;
        }
    }
};

// best to-date: O(1) constant time
// solution: by definition the remainder of a division is that which must be substracted
// from the given bound so as to yield a whole multiple

const maxMultiple = (divisor, bound) => bound - bound % divisor;

/* 
    Prompt
    Given a Divisor and a Bound , Find the largest integer N , Such That ,

    Conditions :
      - N is divisible by divisor
      - N is less than or equal to bound
      - N is greater than 0.

*/