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Function promisification

Nov 19, 2022CodeCatch
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tree traversal

Nov 19, 2022CodeCatch

0 likes • 1 view

class TreeNode {
constructor(key, value = key, parent = null) {
this.key = key;
this.value = value;
this.parent = parent;
this.children = [];
}
get isLeaf() {
return this.children.length === 0;
}
get hasChildren() {
return !this.isLeaf;
}
}
class Tree {
constructor(key, value = key) {
this.root = new TreeNode(key, value);
}
*preOrderTraversal(node = this.root) {
yield node;
if (node.children.length) {
for (let child of node.children) {
yield* this.preOrderTraversal(child);
}
}
}
*postOrderTraversal(node = this.root) {
if (node.children.length) {
for (let child of node.children) {
yield* this.postOrderTraversal(child);
}
}
yield node;
}
insert(parentNodeKey, key, value = key) {
for (let node of this.preOrderTraversal()) {
if (node.key === parentNodeKey) {
node.children.push(new TreeNode(key, value, node));
return true;
}
}
return false;
}
remove(key) {
for (let node of this.preOrderTraversal()) {
const filtered = node.children.filter(c => c.key !== key);
if (filtered.length !== node.children.length) {
node.children = filtered;
return true;
}
}
return false;
}
find(key) {
for (let node of this.preOrderTraversal()) {
if (node.key === key) return node;
}
return undefined;
}
}
const tree = new Tree(1, 'AB');
tree.insert(1, 11, 'AC');
tree.insert(1, 12, 'BC');
tree.insert(12, 121, 'BG');
[...tree.preOrderTraversal()].map(x => x.value);
// ['AB', 'AC', 'BC', 'BCG']
tree.root.value; // 'AB'
tree.root.hasChildren; // true
tree.find(12).isLeaf; // false
tree.find(121).isLeaf; // true
tree.find(121).parent.value; // 'BC'
tree.remove(12);
[...tree.postOrderTraversal()].map(x => x.value);
// ['AC', 'AB']
function printHeap(heap, index, level) {
if (index >= heap.length) {
return;
}
console.log(" ".repeat(level) + heap[index]);
printHeap(heap, 2 * index + 1, level + 1);
printHeap(heap, 2 * index + 2, level + 1);
}
//You can call this function by passing in the heap array and the index of the root node, which is typically 0, and level = 0.
let heap = [3, 8, 7, 15, 17, 30, 35, 2, 4, 5, 9];
printHeap(heap,0,0)

LeetCode Two Sum

Sep 13, 2023C S

0 likes • 2 views

/**
* @param {number[]} nums
* @param {number} target
* @return {number[]}
*/
var twoSum = function(nums, target) {
for(let i = 0; i < nums.length; i++) {
for(let j = 0; j < nums.length; j++) {
if(nums[i] + nums[j] === target && i !== j) {
return [i, j]
}
}
}
};

typewriter-effect in Vanilla JS and React

Jan 25, 2023C S

0 likes • 8 views

// Vanilla JS Solution:
var app = document.getElementById('app');
var typewriter = new Typewriter(app, { loop: true });
typewriter
.typeString("I'm John and I'm a super cool web developer")
.pauseFor(3000)
.deleteChars(13) // "web developer" = 13 characters
.typeString("person to talk with!") // Will display "I'm John and I'm a super cool person to talk with!"
.start();
// React Solution:
import Typewriter from 'typewriter-effect';
<Typewriter
options={{ loop: true }}
onInit={typewriter => {
typewriter
.typeString("I'm John and I'm a super cool web developer")
.pauseFor(3000)
.deleteChars(13) // "web developer" = 13 characters
.typeString("person to talk with!") // Will display "I'm John and I'm a super cool person to talk with!"
.start();
}}
/>

Temperature Converter

Nov 19, 2022CodeCatch

0 likes • 2 views

const celsiusToFahrenheit = (celsius) => celsius * 9/5 + 32;
const fahrenheitToCelsius = (fahrenheit) => (fahrenheit - 32) * 5/9;
// Examples
celsiusToFahrenheit(15); // 59
celsiusToFahrenheit(0); // 32
celsiusToFahrenheit(-20); // -4
fahrenheitToCelsius(59); // 15
fahrenheitToCelsius(32); // 0

Flatten an array

Nov 19, 2022CodeCatch

0 likes • 3 views

const flat = arr => [].concat.apply([], arr.map(a => Array.isArray(a) ? flat(a) : a));
// Or
const flat = arr => arr.reduce((a, b) => Array.isArray(b) ? [...a, ...flat(b)] : [...a, b], []);
// Or
// See the browser compatibility at https://caniuse.com/#feat=array-flat
const flat = arr => arr.flat();
// Example
flat(['cat', ['lion', 'tiger']]); // ['cat', 'lion', 'tiger']