Some of Js Challenge Questions-2

// 1. Write a function for strings that return a string that's repeating the string
// for a given integer number for instance, given `"hello".repeatify(3)` expression
// should return "hello, hello, hello" as an output

String.prototype.repeatify = function (param) {
  let result = "";
  for (let i = 0; i < param; i++) result += `, ${this}`;
  return result.slice(1).trim();
};

// console.log("hello".repeatify(3));

// 2. Write a function that finds occurences count of a given word as a whole inside given string

const findWholeWordInAPool = (word = "word", pool = "dworsdfwsodrwword") => {
  let regexp = new RegExp(word);
  return (pool.match(regexp) || []).length;
};

// console.log(findWholeWordInAPool());

// 3. Write a function that finds occurences count of a given word as a seperate letters inside given string

const findOccurencesOfWord = (
  word = "word",
  pool = "dworsdfwsodrwword"
) => {
  let obj = {};

  for (let i = 0; i < word.length; i++) obj[word[i]] = 0;

  for (let i = 0; i < pool.length; i++) {
    for (let j = 0; j < word.length; j++) {
      if (pool[i] === word[j]) obj[word[j]] += 1;
    }
  }

  return Object.values(obj).sort((a, b) => a - b)[0];
};

// console.log(findOccurencesOfWord());

// 4. Write a function that return a bool value whether any 3 values of given
// numbers array, include sum of numbers as an element within same array or not

function hasSumOfNumbers(array = [0, 1, 2, -1, 5, -3, 4]) {
  for (let i = 0; i < array.length - 2; i++) {
    for (let j = i + 1; j < array.length - 1; j++) {
      for (let k = j + 1; k < array.length; k++) {
        if (array[i] + array[j] + array[k] === 0) return true;
      }
    }
  }
  return false;
}

console.log(hasSumOfNumbers());
// O(n^3)

// 5. Given an array of integers, find the pair of adjacent elements that
// has the largest product and return that product. For instance, for a
// numbers array of inputArray = [3, 6, -2, -5, 7, 3], the output should
// be 21 since 7 and 3 produce the largest number.

function adjacentElementsProduct (inputArray) {
    let max = 0,
        sum = 0,
        sums = new Array(),
        sortedSums = new Array(),
        negativesCount = 0;
    
    for (let i = 0; i < inputArray.length - 1; i++) {
        sum = inputArray[i] * inputArray[i + 1];
        if (sum > max) max = sum;
        else sums.push(sum);
    }
    
    if (max === 0) {
        sums.forEach((value, index) => {
            if (value < 0) negativesCount++;
            if (index === sums.length - 1 && negativesCount === sums.length) {
                sortedSums = sums.sort((a, b) => a - b);
                max = sortedSums[sortedSums.length - 1];
            }
        })
    }
    
    return max;
}

// console.log(adjacentElementsProduct());