SDE - Intern

Ninjas are trying to hack a system of a terrorist organization so that they can know where they will be going to attack next. But to hack the system and to get access to data they need a password that must satisfy certain conditions as described below:

1) Length of the password must be between 8 to 15 characters.
2) At least one digit (0-9), one lowercase letter (a-z), one uppercase letter (A-Z) and one special character (%, ^, &, #, *, %, etc) must be present.
3) Password must not contain any space.

You are given a string ‘STR’, help ninjas to find whether it's a valid password or not.

For example :

Given ‘STR’ =  “Codingninja#1” As it satisfies all the above conditions so it is a valid password and therefore you have to return true.

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?

You have been given a Binary Tree of distinct integers and two nodes ‘X’ and ‘Y’. You are supposed to return the LCA (Lowest Common Ancestor) of ‘X’ and ‘Y’.

The LCA of ‘X’ and ‘Y’ in the binary tree is the shared ancestor of ‘X’ and ‘Y’ that is located farthest from the root.

Note :

You may assume that given ‘X’ and ‘Y’ definitely exist in the given binary tree.

For example :

For the given binary tree

LCA of ‘X’ and ‘Y’ is highlighted in yellow colour.

What do you do to relieve stress? Tell me something outside of your academics.