SDE - 1

You're given a string 'S' consisting of "{", "}", "(", ")", "[" and "]" .

Return true if the given string 'S' is balanced, else return false.

For example:

'S' = "{}()".

There is always an opening brace before a closing brace i.e. '{' before '}', '(' before ').
So the 'S' is Balanced.

You have been given a 2-D array 'mat' of size 'M x N' where 'M' and 'N' denote the number of rows and columns, respectively. The elements of each row are sorted in non-decreasing order.

Moreover, the first element of a row is greater than the last element of the previous row (if it exists).

You are given an integer ‘target’, and your task is to find if it exists in the given 'mat' or not.

Example:

Input: ‘M’ = 3, 'N' = 4, ‘mat’ = [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]], ‘target’ = 8

Output: true

Explanation: The output should be true as '8' exists in the matrix.

You are given two strings S and X containing random characters. Your task is to find the smallest substring in S which contains all the characters present in X.

Example:

Let S = “abdd” and X = “bd”.

The windows in S which contain all the characters in X are: 'abdd', 'abd', 'bdd', 'bd'. 
Out of these, the smallest substring in S which contains all the characters present in X is 'bd'. 
All the other substring have a length larger than 'bd'.

You are given an arbitrary binary tree consisting of N nodes where each node is associated with a certain value. You need to check whether the given tree is a sum tree or not.

A binary tree is a sum tree if the value of each node is equal to the sum of nodes present in the left and the right subtree. An empty tree is a sum tree with 0 sums. A leaf node is also considered a sum tree with a sum equal to the value of the leaf node.

I need to write a query that returns the employee with the third highest salary in the company.