wataruoguchi

// https://practice.geeksforgeeks.org/problems/number-of-occurrence/0
// https://www.geeksforgeeks.org/count-number-of-occurrences-or-frequency-in-a-sorted-array/
function numberOfOccurrence(arr, targetNum) {
  return arr.filter((num) => num === targetNum).length || -1;
}
const nums1 = [1,1,2,2,2,2,3];
const result1 = numberOfOccurrence(nums1,2);
console.log(result1 === 4);
const nums2 = [1,1,2,2,2,2,3];
const result2 = numberOfOccurrence(nums2,4);

wataruoguchi

// https://practice.geeksforgeeks.org/problems/stickler-theif/0
function sticklerTheif(houses) {
  function getAmount(condition) {
    return (acc, house, idx) => {
      if (condition(idx)) {
        acc += house;
      }
      return acc;
    }
  }

wataruoguchi

// https://www.geeksforgeeks.org/k-largestor-smallest-elements-in-an-array/
// https://practice.geeksforgeeks.org/problems/k-largest-elements/0
function kLargest(arr, n, k) {
  return arr.sort((a, b) => b - a).splice(0, k);
}
const arrEx1 = [12,5,787,1,23];
const resEx1 = kLargest(arrEx1, arrEx1.length, 2);
console.log(resEx1.join(',') === '787,23');
const arrEx2 = [1,23,12,9,30,2,50];
const resEx2 = kLargest(arrEx2, arrEx2.length, 3);

wataruoguchi

// Program for array rotation
// https://www.geeksforgeeks.org/array-rotation/
function rotate(arr, d, n) {
  // Write a function rotate(ar[], d, n) that rotates arr[] of size n by d elements.
  const stash = arr.splice(0, d);
  return arr.concat(stash);
}

const arr = [1,2,3,4,5,6,7];
const res = rotate(arr, 2, arr.length);

wataruoguchi

// Given a sorted circularly linked list of Nodes that store integers and a new Node, Insert the new Node into the correct position. (Duplicates allowed)
class Node {
  constructor(val, next) {
    this.val = val;
    this.next = next;
  }
}
function printList(head) {
  let tmp = head;
  let arr = [];

wataruoguchi

// https://www.geeksforgeeks.org/reverse-a-list-in-groups-of-given-size/
class Node {
  constructor(val, next) {
    this.val = val;
    this.next = next;
  }
}
function printList(head) {
  let tmp = head;
  let arr = [];

wataruoguchi

// https://www.geeksforgeeks.org/flattening-a-linked-list/
// https://www.youtube.com/watch?v=PSKZJDtitZw
function printList(root) {
  let tmp = root;
  let arr = [];
  while (tmp) {
    arr.push(tmp.val);
    tmp = tmp.down;
  }
  return arr;

wataruoguchi

// https://www.geeksforgeeks.org/detect-and-remove-loop-in-a-linked-list/
function printList(root) {
  let tmp = root;
  let arr = [];
  while (tmp) {
    arr.push(tmp.val);
    tmp = tmp.next;
  }
  return arr;
}

wataruoguchi

// https://www.geeksforgeeks.org/add-two-numbers-represented-by-linked-lists-set-3/
// Same - https://www.geeksforgeeks.org/add-two-numbers-represented-by-linked-lists/
function printList(root) {
  let tmp = root;
  let arr = [];
  while (tmp) {
    arr.push(tmp.val);
    tmp = tmp.next;
  }
  return arr;

wataruoguchi

// https://www.geeksforgeeks.org/linked-list-set-1-introduction/
class Node {
  constructor(val, next) {
    this.val = val;
    this.next = next;
  }
}

function printList(list) {
  // O(N)