Software Testing Engineer

You are given a string ‘S’ containing only the characters ‘)’ and ‘(‘. You need to find the length of the longest valid i.e. well-formed parentheses substring.

For example:

Let the given string be “(()())((”.

Here the valid parentheses substrings are: “()”, “()” and “(()())”. Out of these the longest valid string is “(()())” which has a length 6.

You are given an array 'ARR' of integers of length N. Your task is to find the first missing positive integer in linear time and constant space. In other words, find the lowest positive integer that does not exist in the array. The array can have negative numbers as well.

For example, the input [3, 4, -1, 1] should give output 2 because it is the smallest positive number that is missing in the input array.

Given the count of total stones in a game. Two-player ‘Ale’ and ‘Bob’ are playing the game. Your task is to find who will win the game if both the players are playing optimally.

Rules of the game.

1. In a single turn, a player can choose a single stone or ‘even’ number of stones.

2. They will play alternatively, which means in the first chance ‘Ale’ will collect the stones, in second-chance ‘Bob’ will collect the stones. And always ‘Ale’ will start the game.

3. If any player is not able to take any stones then another player will win the game.

You are given a set of ‘N’ rectangular envelopes. The height and width of each envelope are given by arrays, ‘height’ and ‘width’ respectively, each consisting of ‘N’ positive integers. The height, width of the ith envelope is given by ‘height[i]’ and ‘width[i]’ respectively.

You can put one envelope inside another envelope if and only if both the height and width of one envelope is strictly greater than the height and width of the other envelope.

What is the maximum number of envelopes you can Russian doll? (put one inside other)

Note

Rotation of envelope is not allowed, that is, height and width can’t be exchanged

You have been given a singly Linked List of 'N' nodes with integer data and an integer 'K'.

Your task is to remove the 'K'th node from the end of the given Linked List and return the head of the modified linked list.

Example:

Input : 1 -> 2 -> 3 -> 4 -> 'NULL'  and  'K' = 2
Output: 1 -> 2 -> 4 -> 'NULL'
Explanation:
After removing the second node from the end, the linked list become 1 -> 2 -> 4 -> 'NULL'.

Given two sorted arrays 'a' and 'b' of size 'n' and 'm' respectively.

Find the median of the two sorted arrays.

Median is defined as the middle value of a sorted list of numbers. In case the length of list is even, median is the average of the two middle elements.

The expected time complexity is O(min(logn, logm)), where 'n' and 'm' are the sizes of arrays 'a' and 'b', respectively, and the expected space complexity is O(1).

Example:

Input: 'a' = [2, 4, 6] and 'b' = [1, 3, 5]

Output: 3.5

Explanation: The array after merging 'a' and 'b' will be { 1, 2, 3, 4, 5, 6 }. Here two medians are 3 and 4. So the median will be the average of 3 and 4, which is 3.5.