Simple Array Sum Javascript

HackerRank.com Simple Array Sum Javascript

 var sum = 0;  
 function processData(input) {  
   var lines = input.split("\n");  
   var n = parseInt(lines[0]);  
   var arr = lines[1].split(" ");  
   for (var i = 0; i < input.length; i++) {  
     sum += parseInt(arr[i]);  
   }  
   console.log(sum);  
 }   
   
 process.stdin.resume();  
 process.stdin.setEncoding("ascii");  
 _input = "";  
 process.stdin.on("data", function (input) {  
   _input += input;  
 });  
   
 process.stdin.on("end", function () {  
   processData(_input);  
 });  
   

Two Sum via C#

Problem: Given an array of integers, find two numbers such that they add up to a specific target number.

Answer via C# using HashTable:

 public class Solution {  
   public int[] TwoSum(int[] nums, int target) {  
     List<int> arr = new List<int>();  
     Hashtable hashTable = new Hashtable();  
     for (int i = 0; i < nums.Length;i++)  
     {  
       hashTable[nums[i]] = i;  
     }  
       
     for (int i = 0; i < nums.Length; i++)  
     {  
       // get key2, index2  
       var key2 = target - nums[i];  
       if (hashTable.Contains(key2) && ((Int32)hashTable[key2] != i) && ((Int32)hashTable[key2] > i))  
       {  
         int i2 = (Int32)hashTable[key2];  
         arr.Add(i + 1);  
         arr.Add(i2 + 1);  
       }  
     }  
       
     return arr.ToArray();  
   }  
 }  

Leetcode

Rotate Array via Javascript

Leetcode rotate array via Javascript using reversal:

 /**  
  * @param {number[]} nums  
  * @param {number} k  
  * @return {void} Do not return anything, modify nums in-place instead.  
  */  
 var rotate = function(nums, k) {  
   if(nums.length === 0) {  
    throw "provide valid array";  
   }  
      k = k % nums.length;  
    
   //length of first part  
   var a = nums.length - k;   
    
   reverse(nums, 0, a-1);  
   reverse(nums, a, nums.length-1);  
   reverse(nums, 0, nums.length-1);  
 };  
   
 function reverse(arr, left, right){  
   while(left < right){  
     var temp = arr[left];  
     arr[left] = arr[right];  
     arr[right] = temp;  
     left++;  
     right--;  
   }    
 }  

JSFiddle
Source
Leetcode