Intern

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 two sorted linked lists. You have to merge them to produce a combined sorted linked list. You need to return the head of the final linked list.

Note:

The given linked lists may or may not be null.

For example:

If the first list is: 1 -> 4 -> 5 -> NULL and the second list is: 2 -> 3 -> 5 -> NULL

The final list would be: 1 -> 2 -> 3 -> 4 -> 5 -> 5 -> NULL

You are given an array/list 'prices' where the elements of the array represent the prices of the stock as they were yesterday and indices of the array represent minutes. Your task is to find and return the maximum profit you can make by buying and selling the stock. You can buy and sell the stock only once.

Note:

You can’t sell without buying first.

For Example:

For the given array [ 2, 100, 150, 120],
The maximum profit can be achieved by buying the stock at minute 0 when its price is Rs. 2 and selling it at minute 2 when its price is Rs. 150.
So, the output will be 148.