MohammedALREAI

// TimeColextity nlog(n) space (1)

function twoNumberSum(array:Array<number>, targetSum:number):Array<number|undefined>{

    // we need to sort array 
    let sortArr= array.sort((a,b)=>a-b);
    let left =0;
    let right=sortArr.length-1;
    while(left<right){
      let sumNumber=sortArr[left]+sortArr[right]

MohammedALREAI

class TreeNode {
    val: number
    left: TreeNode | null
    right: TreeNode | null
    constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
        this.val = (val===undefined ? 0 : val)
        this.left = (left===undefined ? null : left)
        this.right = (right===undefined ? null : right)
    }
}

MohammedALREAI

function search(nums: number[], target: number): number {
let left=0;
      let right=nums.length-1
   while (left <= right) {
 const middle = Math.floor((left + right) / 2);
 const potentialMatch = nums[middle];
 if (target === potentialMatch) {
 return middle;

MohammedALREAI

function fib(n: number): number {
 const arr = [1, 1];
 let counter = 3;
 while (counter <= n) {
 const nextFib = arr[0] + arr[1];
 arr[0] = arr[1];
 arr[1] = nextFib;
 counter++;
 }
 return n< 1 ? 0: n===1? 1: arr[1] 

MohammedALREAI

function threeNumberSum(array:Array<number>, targetSum:number):Array<Array<number>> {
 array= array.sort((a, b) => a - b);
 const triplets = [];
 for (let i = 0; i < array.length - 2; i++) {
 let left = i + 1;
 let right = array.length - 1;
 while (left < right) {
 const currentSum = array[i] + array[left] + array[right];
 if (currentSum === targetSum) {
 triplets.push([array[i], array[left], array[right]]);

MohammedALREAI

function smallestDifference(arr1:Array<number>,arr2:Array<number>):Array<number>{
arr1=arr1.sort((a,b)=>a-b)
arr2=arr2.sort((a,b)=>a-b)
let p1=0
let p2=0
 let smallest = Infinity;
 let current = Infinity;
 let smallestPair:Array<number> = [];

MohammedALREAI

function moveToEnd(arr:Array<number>,target:number){
  if(arr.includes(target)) return arr
let p1=0
let p2=arr.length-1
while(p1<p2){
    while(arr[p2]===target) p2--;
    if(arr[p1]=== target ){
        swap(arr,p1,p2);
        p1++
    }

MohammedALREAI

function isValid(s:string ):boolean{
   interface matchingBrac{
      [key:string]:string}
    
    const open="{[(";
const close="}])"
 
 const  matchingBrackets:matchingBrac = {
   ')': '(',

MohammedALREAI

interface Imap{
    [key:string]:number
}

function firstNotRepeatingCharacter(s: string="abacabad"): string {


 let map:Imap ={}
    for (let e of s){
        if(e in map){

MohammedALREAI

function firstDuplicate(a: number[]=[2, 1, 3, 5, 3, 2]): number {


 let set = new Set()
    for (let e of a){
        if (set.has(e))
            return e
        else
            set.add(e)
            }