Software Engineer Intern

You are given a QUEUE containing ‘N’ integers and an integer ‘K’. You need to reverse the order of the first ‘K’ elements of the queue, leaving the other elements in the same relative order.

You can only use the standard operations of the QUEUE STL:

1. enqueue(x) : Adds an item x to rear of the queue
2. dequeue() : Removes an item from front of the queue
3. size() : Returns number of elements in the queue.
4. front() : Finds the front element.

For Example:

Let the given queue be { 1, 2, 3, 4, 5 } and K be 3.
You need to reverse the first K integers of Queue which are 1, 2, and 3.
Thus, the final response will be { 3, 2, 1, 4, 5 }.

You are given a table Employees with the following columns:
emp_id, name, department, salary

Write an SQL query to find the second-highest salary in each department.

You are given an array 'a' of size 'n'.

Print the Next Greater Element(NGE) for every element.

The Next Greater Element for an element 'x' is the first element on the right side of 'x' in the array, which is greater than 'x'.

If no greater elements exist to the right of 'x', consider the next greater element as -1.

For example:

Input: 'a' = [7, 12, 1, 20]

Output: NGE = [12, 20, 20, -1]

Explanation: For the given array,

- The next greater element for 7 is 12.

- The next greater element for 12 is 20. 

- The next greater element for 1 is 20. 

- There is no greater element for 20 on the right side. So we consider NGE as -1.

You are given a table Orders with the following columns:
order_id, customer_id, order_date, amount

Write an SQL query to find customers who have placed more than one order on the same day.