SDE - 1

The n-th term of Fibonacci series F(n), where F(n) is a function, is calculated using the following formula -

    F(n) = F(n - 1) + F(n - 2), 
    Where, F(1) = 1, F(2) = 1

Provided 'n' you have to find out the n-th Fibonacci Number. Handle edges cases like when 'n' = 1 or 'n' = 2 by using conditionals like if else and return what's expected.

"Indexing is start from 1"

Example :

Input: 6

Output: 8

Explanation: The number is ‘6’ so we have to find the “6th” Fibonacci number.
So by using the given formula of the Fibonacci series, we get the series:    
[ 1, 1, 2, 3, 5, 8, 13, 21]
So the “6th” element is “8” hence we get the output.

Given an array ‘arr’ of size ‘n’ find the largest element in the array.

Example:

Input: 'n' = 5, 'arr' = [1, 2, 3, 4, 5]

Output: 5

Explanation: From the array {1, 2, 3, 4, 5}, the largest element is 5.

Implement a Stack Data Structure specifically to store integer data using two Queues.

There should be two data members, both being Queues to store the data internally. You may use the inbuilt Queue.

Implement the following public functions :

1. Constructor:
It initializes the data members(queues) as required.

2. push(data) :
This function should take one argument of type integer. It pushes the element into the stack and returns nothing.

3. pop() :
It pops the element from the top of the stack and, in turn, returns the element being popped or deleted. In case the stack is empty, it returns -1.

4. top :
It returns the element being kept at the top of the stack. In case the stack is empty, it returns -1.

5. size() :
It returns the size of the stack at any given instance of time.

6. isEmpty() :
It returns a boolean value indicating whether the stack is empty or not.

Operations Performed on the Stack:

Query-1(Denoted by an integer 1): Pushes an integer data to the stack. (push function)

Query-2(Denoted by an integer 2): Pops the data kept at the top of the stack and returns it to the caller. (pop function)

Query-3(Denoted by an integer 3): Fetches and returns the data being kept at the top of the stack but doesn't remove it, unlike the pop function. (top function)

Query-4(Denoted by an integer 4): Returns the current size of the stack. (size function)

Query-5(Denoted by an integer 5): Returns a boolean value denoting whether the stack is empty or not. (isEmpty function)

Example

Operations: 
1 5
1 10
2
3
4

Enqueue operation 1 5: We insert 5 at the back of the queue.
  Queue: [5]

Enqueue operation 1 10: We insert 10 at the back of the queue.
  Queue: [5, 10]

Dequeue operation 2: We remove the element from the front of the queue, which is 5, and print it.
  Output: 5
  Queue: [10]

Peek operation 3: We return the element present at the front of the queue, which is 10, without removing it.
  Output: 10
  Queue: [10]

IsEmpty operation 4: We check if the queue is empty.
  Output: False
  Queue: [10]

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