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.

A thief is robbing a store and can carry a maximal weight of W into his knapsack. There are N items and the ith item weighs wi and is of value vi. Considering the constraints of the maximum weight that a knapsack can carry, you have to find and return the maximum value that a thief can generate by stealing items.

What is abstract?
Explain encapsulation?
Explain method overriding and method overloading?
What is inheritance and polymorphism?
Difference between abstract class and interface?

Given a singly linked list of integers. Your task is to return the head of the reversed linked list.

For example:

The given linked list is 1 -> 2 -> 3 -> 4-> NULL. Then the reverse linked list is 4 -> 3 -> 2 -> 1 -> NULL and the head of the reversed linked list will be 4.

Follow Up :

Can you solve this problem in O(N) time and O(1) space complexity?