SDE - 1

You are given an array Arr consisting of N integers. You need to find the equilibrium index of the array.

An index is considered as an equilibrium index if the sum of elements of the array to the left of that index is equal to the sum of elements to the right of it.

Note:

1. The array follows 0-based indexing, so you need to return the 0-based index of the element.
2. Note that the element at the equilibrium index won’t be considered for either left sum or right sum.
3. If there are multiple indices which satisfy the given condition, then return the left-most index i.e if there are indices i,j,k…. which are equilibrium indices, return the minimum among them
4. If no such index is present in the array, return -1.

Given an array ARR of N integers and an integer S. The task is to find whether there exists a subarray(positive length) of the given array such that the sum of elements of the subarray equals to S or not. If any subarray is found, return the start and end index (0 based index) of the subarray. Otherwise, consider both the START and END indexes as -1.

Note:

If two or more such subarrays exist, return any subarray.

For Example: If the given array is [1,2,3,4] and the value of S is equal to 7. Then there are two possible subarrays having sums equal to S are [1,2,3] and [3,4].

You have been given a Binary Tree of integers. You are supposed to return the level order traversal of the given tree.

For example:

For the given binary tree

The level order traversal will be {1,2,3,4,5,6,7}.

You are given a string ‘str’ of size ‘N’. Your task is to remove consecutive duplicates from this string recursively.

For example:

If the input string is ‘str’ = ”aazbbby”, then your output will be “azby”.
Note that we are just removing adjacent duplicates.

Tell me a time when you have taken responsibility for a project and given good results.
Tell me a time you have worked under pressure and given an exceptional result.

You are given a Singly Linked List of integers. Return true if it has a cycle, else return false.

A cycle occurs when a node's next points back to a previous node in the list.

Example:

In the given linked list, there is a cycle, hence we return true.

Bob lives with his wife in a city named Berland. Bob is a good husband, so he goes out with his wife every Friday to ‘Arcade’ mall.

‘Arcade’ is a very famous mall in Berland. It has a very unique transportation method between shops. Since the shops in the mall are laying in a straight line, you can jump on a very advanced trampoline from the shop i, and land in any shop between (i) to (i + Arr[i]), where Arr[i] is a constant given for each shop.

There are N shops in the mall, numbered from 0 to N-1. Bob's wife starts her shopping journey from shop 0 and ends it in shop N-1. As the mall is very crowded on Fridays, unfortunately, Bob gets lost from his wife. So he wants to know, what is the minimum number of trampoline jumps from shop 0 he has to make in order to reach shop N-1 and see his wife again. If it is impossible to reach the last shop, return -1.

A binary tree is a tree where each node has at most two children i.e left child and right child.

You are given a binary tree, where the structure of the node is as follow -:

class BinaryTreeNode {
 int data;      // Value of the node.
 BinaryTreeNode *left;  // Pointer to left child node.
 BinaryTreeNode *right; // Pointer to right child node.
 BinaryTreeNode *next;  // Pointer to next right node at same level. 
}

Your task is to connect all the adjacent nodes at the same level in the given binary tree. You can do this by populating each 'next' pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL. Initially, all the next pointers are set to NULL.

For Example:

Consider the figure shown below. The left part represents the initial binary tree and right part represents the binary tree after connecting adjacent nodes at the same level.

In the tree shown in the picture above -:
The ‘next’ pointer of the node having value 2 is connected to the node having value 3.
The ‘next’ pointer of the node having value 4 is connected to the node having value 5.
The ‘next’ pointer of the node having value 5 is connected to the node having value 6.
The ‘next’ pointer of nodes having value 1, 3, 6 will have a value NULL as there are no next right nodes in their cases.

Note:

1. The structure of the ‘Node’ of a binary tree is already defined. You should not change it.   
2. The root of the binary tree is known to you.  
3. There is at least one node in the given binary tree.
4. You may only use constant extra space.