Naive Solution :
A simple solution is to traverse each element and check if there’s another number in the array which can be added to it to give sum.

TC: O(n^2)
SC:O(1)

Efficient Solution (Using Hashing ) :
We create an empty hash table. Now we traverse through the array and check for pairs in the hash table. If a matching element is found, we print the pair number of tim...

Algorithm :
1)Create a recursive function (say TreeNode*build(arr,start,end) ) which returns the root of the newly cretaed BST . The parameters of this function will be the sorted array , left end of the array , right end of the array .

2)Now, find the mid element of the array and make it as the root i.e., 
TreeNode*root=new TreeNode(arr[mid]); where mid=(start+end)/2

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The approach is to use the preorder traversal of the tree to traverse the tree and check that we have visited the current vertical level and if visited then we can check for the smaller horizontal level node and store it. Else we can just update the vertical level as visited and store the node and horizontal level of the current node.

1) We have to create the map to check whether the hor...

Approach 1 : Naive Recursive Approach

A naive approach is to start from the first element and recursively call for all the elements reachable from first element. The minimum number of jumps to reach end from first can be calculated using minimum number of jumps needed to reach end from the elements reachable from first.

minJumps(start, end) = Min ( minJumps(k, end) ) for all k rea...

Tip 1: Firstly, remember that the system design round is extremely open-ended and there’s no such thing as a standard answer. Even for the same question, you’ll have a totally different discussion with different interviewers. 

Tip 2: Before you jump into the solution always clarify all the assumptions you’re making at the beginning of the interview. Ask questions to identify the sco...

Prerequisite to solve this problem : Multithreading

The idea is to create two threads and print even numbers with one thread and odd numbers with another thread. Below are the steps:

1) Create two threads T1 and T2 , where T1 and T2 are used to print odd and even numbers respectively.
2) Maintain a global counter variable and start both threads.
3) If the counter is even in ...