SDE - Intern

Consider a rat placed at (0, 0) in a square matrix of order N * N. It has to reach the destination at (N - 1, N - 1). Find all possible paths that the rat can take to reach from source to destination. The directions in which the rat can move are 'U'(up), 'D'(down), 'L' (left), and 'R' (right). Value 0 at a cell in the matrix represents that it is blocked and the rat cannot move to it while value 1 at a cell in the matrix represents that the rat can travel through it. Note: In a path, no cell can be visited more than one time. If the source cell is 0, the rat cannot move to any other cell.

Given an array, ‘Arr’ of length ‘n’, count the number of longest increasing subsequences (LIS).

You are given two binary trees with 'n' and 'm' nodes respectively.

You need to return true if the two trees are identical. Otherwise, return false.

Example:

For the trees given below:- 

The given trees are identical as:-
1. The number of nodes in both trees is the same. 
2. The number of edges in both trees is the same. 
3. The data for root for both the trees is the same i.e 5. 
4. The data of root -> left (root’s left child) for both the trees is the same i.e 2.
5. The data of root -> right (root’s right child) for both the trees is the same i.e 3.
6. The data of root -> right -> left ( left child of root’s right child) for both the trees is the same i.e 6.
7. Nodes with data 2 and 6 are the leaf nodes for both the binary trees. 

What is a foreign key? (Learn)

Aahad and Harshit always have fun by solving problems. Harshit took a sorted array consisting of distinct integers and rotated it clockwise by an unknown amount. For example, he took a sorted array = [1, 2, 3, 4, 5] and if he rotates it by 2, then the array becomes: [4, 5, 1, 2, 3].

After rotating a sorted array, Aahad needs to answer Q queries asked by Harshit, each of them is described by one integer Q[i]. which Harshit wanted him to search in the array. For each query, if he found it, he had to shout the index of the number, otherwise, he had to shout -1.

For each query, you have to complete the given method where 'key' denotes Q[i]. If the key exists in the array, return the index of the 'key', otherwise, return -1.

Note:

Can you solve each query in O(logN) ?

You are given two strings ‘A’ and ‘B’. Your task is to return a substring ‘S’ of ‘A’ such that the following conditions hold true :

• You can make ‘B’ from ‘S’ by removing some characters and rearranging some characters zero or more times.

• Length of ‘S’ must be as minimum as possible.

Note :

Testcases are generated such that a substring always exists and is unique.

Example :

A = ninjas, B = sin

All possible substrings with which 'B' can be created are
"ninjas", "injas".

Hence the substring with minimum length is "injas".