Programmer Analyst

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.

Ninja is playing with numbers but hates when he gets duplicate numbers. Ninja is provided an array, and he wants to remove all duplicate elements and return the array, but he has to maintain the order in which the elements were supplied to him.

You are given a non-negative integer ‘num’ in the form of a string and provided with an integer ‘k’.

You need to find the smallest integer possible by removing exactly ‘k’ digits from ‘num.’

Note :

‘num’ does not have leading zeros except when ‘num’ equals zero.

Example:

Input: ‘num’ = ‘141’ , ‘k’ = 1.

Output: ‘11’

Explanation: By removing only 1 digit from ‘num’, 3 numbers can be formed: 14, 11, and 41. Out of which 11 is the smallest number.

Note :

You don’t have to print anything. It has already been taken care of. Just implement the given function.

"There are 100 doors in a single row that are all closed. You make 100 passes by each door, starting at the first door each time. On the first time you pass, you visit every door, and if it's closed, you open it, and if it's open, you close it. On your second pass by, you only visit every other door, starting from the second door in line so that you're skip-counting the doors by two. The third pass you go to every third door, the fourth pass every fourth door, and so on until you have only passed by the hundredth door. During your last pass by, which of the doors are still open and which ones are closed?"