SDE - 1

You are given two numbers 'A' and 'B' in the form of two arrays (A[] and B[]) of lengths 'N' and 'M' respectively, where each array element represents a digit. You need to find the sum of these two numbers and return this sum in the form of an array.

Note:

1. The length of each array is greater than zero.

2. The first index of each array is the most significant digit of the number. For example, if the array A[] = {4, 5, 1}, then the integer represented by this array is 451 and array B[] = {3, 4, 5} so the sum will be 451 + 345 = 796. So you need to return {7, 9, 6}.

3. Both numbers do not have any leading zeros in them. And subsequently, the sum should not contain any leading zeros.

Ninja found an old book that has a given tree of numbers. Ninja is interested to find the number of members of that tree that has more children than its parent.

There are ‘N’ nodes in the tree and each node is indexed with a number between 0 to ‘N’-1. The tree is given in a form of an ‘EDGES’ array. Each element of ‘EDGES’ has two values, denoting an edge between that two nodes. The root of the tree is Node 0. Your task is to find the number of nodes having more children than their parent’s node.

For Example

For the given ‘EDGES’ = [ [0,1],[1,2],[1,3],[1,4] ] and ‘N’ = 5.The number of nodes satisfying the condition is 1. Only Node 1 satisfies the given condition.

You are given two Strings 'P' and 'Q' of equal length.

Your task is to return 1 if String 'P' can be converted into String 'Q' by cyclically rotating it to the right any number of times ( Possibly Zero ), else return 0.

A cyclic rotation to the right on String 'A' consists of taking String 'A' and moving the rightmost character to the leftmost position. For example, if 'A' = "pqrst", then it will be "tpqrs" after one cyclic rotation on 'A'.

For example:

Consider the two strings 'P' = "abfyg" and 'Q' = "gabfy" 

If we cyclically rotate String 'P' to the right once. The resulting string P becomes "gabfy" which is equal to String 'Q'. 

Therefore it is possible to convert String 'P' to String 'Q'.

What is an efficient way to implement a singleton pattern in Java? Give me an code example

There are some questions based on Linked list, tree, stack, array, heap sort definition and structures. Also I have to define them in my own way.