SDE - 1

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.

You have been given 'N' ropes of different lengths, we need to connect these ropes into one rope. The cost to connect two ropes is equal to sum of their lengths. We need to connect the ropes with minimum cost.

The test-data is such that the result will fit into a 32-bit integer.

Alok has three daughters. His friend Shyam wants to know the ages of his daughters. Alok gives him a first hint. 

1. The product of their age is 72. 
Shyam says this is not enough information. Alok gives him a second hint. 

2. The sum of their ages is equal to my house number. 
Shyam goes out and looks at the house number and tells, “I still do not have enough information to determine the ages”. Alok admits that Shyam can not guess and gives him the third hint 

3. The oldest girl likes strawberry ice cream. 
Shyam is able to guess after the third hint. Can you guess what the ages of the three daughters are? 

You have been given a binary tree of integers. You are supposed to find the left view of the binary tree. The left view of a binary tree is the set of all nodes that are visible when the binary tree is viewed from the left side.

Example:

The left view of the above binary tree is  {5, 7, 14, 25}.

A thief wants to loot houses. He knows the amount of money in each house. He cannot loot two consecutive houses. Find the maximum amount of money he can loot.