SDE - 1

You are given an array ‘ARR’ of length ‘N’ which is filled with the values such that ARR[i] = (2*i + 1). You have to perform operations on the ‘ARR’ to make all elements of the array equal. In one operation, you can choose two elements from the array ‘ARR’ say ‘i’ and ‘j’, and can increment the value of ‘ARR[i]’ by one and decrement the value of ‘ARR[j]’ by one.

You have to find the minimum number of operations to make all the elements of the array ‘ARR’ equal. It is guaranteed that all elements of the array can be made equal using some operations.

Given an array/list of integers of length ‘N’, there is a sliding window of size ‘K’ which moves from the beginning of the array, to the very end. You can only see the ‘K’ numbers in a particular window at a time. For each of the 'N'-'K'+1 different windows thus formed, you are supposed to return the maximum element in each of them, from the given array/list.

Ninja has been given an array/list of integers ‘ARR’ of size ‘N’. Ninja has to find the greatest number present in the ‘ARR’ such that this number is also equal to the product of the two elements present in the ‘ARR’.

Note:

1. The pair should be from different indices. 
2. If no such number is present in the ‘ARR’, then return -1.

You are given a binary tree having ‘N’ distinct nodes and an integer ‘M’, you have to return the postorder successor of ‘M’.

Note:

The postorder successor of ‘M’ is defined as the next element to ‘M’ in the sequence of postorder traversal.

If the postorder traversal of a tree is 3 5 4 7 then the postorder successor of 5 is the next element to 5 i.e 4.

Return ‘-1’ if there is no postorder successor of ‘M’.

You are given an arbitrary binary tree consisting of N nodes. Your task is to find the largest subtree sum.

Note :

1. The value of any node will not be equal to zero.
2. Subtree of a node X is all the nodes that are below X and X itself.
3. For example in the tree given below, nodes 1, 2 and 3 are in subtree of 1.

4. Subtree sum of X is the sum value of all the nodes in subtree of X.  
5. Binary tree is a tree wherein each node has at most two children.  
6. Any two nodes may have the same value associated with it.

You are given ‘N’ tasks. Each task has its own duration and deadline stored in array/list 'ARR'. You have to do all the tasks. Reward earned by doing a task is ‘deadline of the task’ - ‘time when the task is done’.

You have to order the tasks in such a way that the sum of rewards is maximized and find the maximum sum of the reward.

Note :

1. The time starts from zero. 
2. Before completing one task another task can not be started. 
3. The reward for doing a task can be negative.