SDE - 1

You are given an array Arr consisting of N integers. Your task is to find all the unique permutations of the given array. For e.g if the array is {1, 1, 2}, the unique permutations of this array are {1, 1, 2}, {1, 2, 1}, {2, 1, 1}. Note that the total number of permutations of {1,1,2} is equal to 6 but out of those {1,1,2} and {1,2,1} occur twice.

Note:

1. There might be duplicates present in the array.
2. The order of the permutations in the output does not matter.
3. Do not use any kind of in-built library functions to find the answer.

You are given an array ‘ARR’ consisting of ‘N’ strings. Your task is to find the longest common prefix among all these strings. If there is no common prefix, you have to return an empty string.

A prefix of a string can be defined as a substring obtained after removing some or all characters from the end of the string.

For Example:

Consider ARR = [“coding”, ”codezen”, ”codingninja”, ”coders”]
The longest common prefix among all the given strings is “cod” as it is present as a prefix in all strings. Hence, the answer is “cod”.

You have been given a number of stairs. Initially, you are at the 0th stair, and you need to reach the Nth stair.

Each time, you can climb either one step or two steps.

You are supposed to return the number of distinct ways you can climb from the 0th step to the Nth step.

Note:

Note: Since the number of ways can be very large, return the answer modulo 1000000007.

Example :

N=3

We can climb one step at a time i.e. {(0, 1) ,(1, 2),(2,3)} or we can climb the first two-step and then one step i.e. {(0,2),(1, 3)} or we can climb first one step and then two step i.e. {(0,1), (1,3)}.

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'.

You have got someone working for you for five days and a gold bar to pay him. You must give them a piece of gold at the end of every day. What are the fewest number of cuts to the bar of gold that will allow you to pay him 1/5th each day?