How to move elements in a queue

Question

Discuss the below:

Q: Write a function

template

void n2front (queue& q, int n);

that moves the nth element (counting from the front, which is element 1) of the queue to the front, leaving the order of all other elements unchanged. The function throws the rangeError exception if n < 1 or n> q.size(). The figure illustrates the action of n2front() for an integer queue and n = 4.

n = 4 (4^th element of queue)

Before

8

5

17

3

7

front                                                                                 back

After

3

8

5

17

7

front                                                                                 back