Skip to main content

linear search

Nov 19, 2022CodeCatch
Loading...

More JavaScript Posts

typewriter-effect in Vanilla JS and React

Jan 25, 2023C S

0 likes • 7 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();
}}
/>

count substrings

Nov 19, 2022CodeCatch

0 likes • 0 views

const countSubstrings = (str, searchValue) => {
let count = 0,
i = 0;
while (true) {
const r = str.indexOf(searchValue, i);
if (r !== -1) [count, i] = [count + 1, r + 1];
else return count;
}
};
countSubstrings('tiktok tok tok tik tok tik', 'tik'); // 3
countSubstrings('tutut tut tut', 'tut'); // 4

compact object

Nov 19, 2022CodeCatch

0 likes • 0 views

const compactObject = val => {
const data = Array.isArray(val) ? val.filter(Boolean) : val;
return Object.keys(data).reduce(
(acc, key) => {
const value = data[key];
if (Boolean(value))
acc[key] = typeof value === 'object' ? compactObject(value) : value;
return acc;
},
Array.isArray(val) ? [] : {}
);
};
const obj = {
a: null,
b: false,
c: true,
d: 0,
e: 1,
f: '',
g: 'a',
h: [null, false, '', true, 1, 'a'],
i: { j: 0, k: false, l: 'a' }
};
compactObject(obj);
// { c: true, e: 1, g: 'a', h: [ true, 1, 'a' ], i: { l: 'a' } }

binary search

Nov 19, 2022CodeCatch

0 likes • 3 views

const binarySearch = (arr, item) => {
let l = 0,
r = arr.length - 1;
while (l <= r) {
const mid = Math.floor((l + r) / 2);
const guess = arr[mid];
if (guess === item) return mid;
if (guess > item) r = mid - 1;
else l = mid + 1;
}
return -1;
};
binarySearch([1, 2, 3, 4, 5], 1); // 0
binarySearch([1, 2, 3, 4, 5], 5); // 4
binarySearch([1, 2, 3, 4, 5], 6); // -1

LeetCode Product Except Self

Sep 13, 2023C S

0 likes • 11 views

/**
* @param {number[]} nums
* @return {number[]}
*/
var productExceptSelf = function(nums) {
var output = [];
var leftMult = 1;
var rightMult = 1;
for (var i=nums.length - 1; i >= 0; i--) {
output[i] = rightMult;
rightMult *= nums[i];
console.log({output: JSON.stringify(output), i})
}
for (var j=0; j < nums.length; j++) {
output[j] *= leftMult;
leftMult *= nums[j];
console.log({output: JSON.stringify(output), j})
}
return output;
};
console.log(productExceptSelf([1, 2, 3, 4]))

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']