Question

write a function to insert an element in the middle of a queue. Please use C++ and make sure its a function. Thanks

Answer 1

#include <stdio.h>

#define MAX 100
void enqueue(int a);
void insert_middle(int a); // insert the lement into the middle function
void display();
int queue[MAX];
int rear = -1;
int front = -1;

int main()
{
enqueue(1);
enqueue(2);
enqueue(3);
enqueue(4);
printf("Before inserting the element 5 into the middle : \n");
display();
insert_middle(5);
printf("After inserting the element 5 into the middle : \n");
display();
}

void enqueue(int a)
{
if(rear == MAX - 1)
{
printf("overflow"); // if it reaches to the maximm limit
}
else
{
if(front == - 1)
{
front = 0;
}
rear++;
queue[rear] = a;
}
}

void insert_middle(int a) // function for inserting the lement into the middle of the queue
{
int i;
for(i = rear; i >= (rear + 1) / 2; i--) // move the element for the second half to the consecutive locations
{
queue[i + 1] = queue[i];
}
queue[(rear + 1) / 2] = a; // place the value into the middle
rear++;
}

void display()
{
for(int i = front; i <= rear; i++) // displaying the elements in the queue format
{
printf("%d ", queue[i]);
}
printf("\n");
}

OUTPUT :

Before inserting the element 5 into the middle : 1 2 3 4 After inserting the element 5 into the middle : 1 2 5 3 4 ... Program finished with exit code o Press ENTER to exit console.O