SDE - 1

You are given an array containing 'N' points in the plane. The task is to find out the distance of the closest points.

Note :

Where distance between two points (x1, y1) and (x2, y2) is calculated as [(x1 - x2) ^ 2] + [(y1 - y2) ^ 2].

You are given a string 'str' of length 'N'.

Your task is to return the longest palindromic substring. If there are multiple strings, return any.

A substring is a contiguous segment of a string.

For example :

str = "ababc"

The longest palindromic substring of "ababc" is "aba", since "aba" is a palindrome and it is the longest substring of length 3 which is a palindrome. 

There is another palindromic substring of length 3 is "bab". Since starting index of "aba" is less than "bab", so "aba" is the answer.

You are given a sorted array ‘arr’ of ‘n’ numbers such that every number occurred twice in the array except one, which appears only once.

Return the number that appears once.

Example:

Input: 'arr' = [1,1,2,2,4,5,5]

Output: 4 

Explanation: 
Number 4 only appears once the array.

Note :

Exactly one number in the array 'arr' appears once.

You are given an array 'a' of size 'n'.

Print the Next Greater Element(NGE) for every element.

The Next Greater Element for an element 'x' is the first element on the right side of 'x' in the array, which is greater than 'x'.

If no greater elements exist to the right of 'x', consider the next greater element as -1.

For example:

Input: 'a' = [7, 12, 1, 20]

Output: NGE = [12, 20, 20, -1]

Explanation: For the given array,

- The next greater element for 7 is 12.

- The next greater element for 12 is 20. 

- The next greater element for 1 is 20. 

- There is no greater element for 20 on the right side. So we consider NGE as -1.

You are given an ‘N’ x ‘M’ matrix ‘MAT’ and an integer ‘K’. Your task is to find the maximum sum of a rectangle in the matrix which is less than or equal to ‘K’.

For Example:

You are given ‘MAT’= [[1, 2],[3, 4]] and ‘K’ = 8. 

Then the answer will be 7 (the sum of the red rectangle).

Its was a frog jumping version of Triangle Golf Tee Puzzle.

You are given a list of ‘N’ words ‘WORDS’. Your task is to return all pairs of the distinct indices (i, j) in ‘WORDS’, such that the concatenation of WORDS[i] and WORDS[j] is a palindrome.

For Example:

You are given ‘WORDS’ = [“cat”, “mat”, “tac”]. Then the answer will be [(0, 2), (2, 0)}, because “cat” + “tac” = “cattac” which is a palindrome and “tac” + “cat” = “taccat” which is also a palindrome.

Given an array arr of length N consisting of positive and negative integers, return the length of the longest subarray whose sum is zero.

You are given two binary search trees of integers having ‘N’ and ‘M’ nodes. Return an array that contains elements of both BST in sorted order.

A binary search tree (BST) is a binary tree data structure with the following properties.

• The left subtree of a node contains only nodes with data less than the node’s data.

• The right subtree of a node contains only nodes with data greater than the node’s data.

• Both the left and right subtrees must also be binary search trees.

You are given an ‘M*N’ Matrix, You need to print all possible paths from its top left corner to the bottom right corner if given that you can either move right i.e from (i,j) to (i,j+1) or down i.e from (i, j) to (i+1, j).

For Example :

1 2 3
4 5 6

For the above 2*3 matrix , possible paths are (1 2 3 6) , (1 2 5 6) , (1 4 5 6).

Note :

You can return the paths in any order.