SDE - Intern

You are given an array ‘arr’ of size ‘N’. You are provided with ‘Q’ queries, each containing two integers, ‘L’ and ‘R’. Your task is to return the sum of elements from the position ‘L’ to ‘R’ for each query.

For example:

You are given arr = [1, 3, 4, 5, 6, 9], and queries = [[1, 3], [5, 6] , [1, 6]].

For the first query [1, 3] sum of elements = 1 + 3 + 4 = 8. Hence the answer is 8

For the second query [5, 6] sum of elements = 6 + 9 = 15. Hence the answer is 15

For the third query [1, 6] sum of elements = 1 + 3 + 4 + 5 + 6 + 9= 28. Hence the answer is 28. 

Hence the final answer is [8, 15, 28]

You are given two strings, string A and string B. Your task is to determine whether string A can be transformed into string B by performing only one of the following operations at most one (or maybe zero) time.

1. You can delete a character from any position.
2. You can replace a character with any other character.
3. You can insert a character at any position. 

Note :

1. The strings are non-empty.
2. The strings only contain lowercase English letters.

You have been given a non-empty grid consisting of only 0s and 1s. You have to find the number of islands in the given grid.

An island is a group of 1s (representing land) connected horizontally, vertically or diagonally. You can assume that all four edges of the grid are surrounded by 0s (representing water).

You are given two arbitrary binary trees consisting of N and M number of nodes respectively, your task is to check whether the two trees are mirror of each other or not.

Two trees are said to be mirror of each other, if

1. Roots of both the given trees are same.
2. Left subtree of the root of the first tree is the mirror of the right subtree of the root of the second tree.
3. Right subtree of the root of the first tree is the mirror of the left subtree of the root of the second tree.

For example,both the given trees are mirror image of each other:

Ninja has been given a string ‘STR’ containing ‘(‘ and ‘)’. ‘STR’ may also contain lower case alphabets. In order to make ‘STR’ valid Ninja can remove either ‘)’ or ‘(’ from ‘STR’.

Here are some examples of valid ‘STR’ “((a))”, “(g)()”, “(())()”, "" (an empty string is also a valid string).

Ninja wants to know all the possible valid strings that can be formed from ‘STR’ by minimum possible removals (possibly zero).

Can you help Ninja to generate all valid strings from ‘STR’ by minimum removals?

For Example :

For the given ‘STR’ =  “()(()”, we can form a valid string “()()” by removing ‘(‘ at index 2 or 3.