Else, the access element is pointed out by ‘front’.If empty, display an underflow error and exit.Add an element to the location pointed by ‘rear’.ĭequeue operation consists of the following steps:.If full, produce overflow error and exit.In this process, the following steps are performed: peek: Gets an element at the front of the queue without removing it.An item is removed or de-queued always from the front of the queue.
DeQueue: Removes an item from the queue.Addition of an item to the queue is always done at the rear of the queue. The queue data structure includes the following operations: When the front is null, then the queue is empty. When the rear pointer value is size-1, then we say that the queue is full. The operation to remove/delete elements from the queue is called “dequeue”. The “front” end pointer is the place from where the elements are removed from the queue. The operation of adding /inserting elements in the queue is called “enqueue”. The “rear” end pointer is the place from where the elements are inserted in the queue. When the queue is empty, then both the pointers are set to -1.
STACK VS QUEUE SOFTWARE
Then you need to use the stack, which is faster and easier.In software terms, the queue can be viewed as a set or collection of elements as shown below.
However, If you are working with relatively small variables that are only required until the function using them is alive. For example, you want to create a large size array or big structure to keep that variable around a long time then you should allocate it on the heap. You should use heap when you require to allocate a large block of memory. It takes too much time in execution compared to the stack.Memory management is more complicated in heap memory as it is used globally.It can provide the maximum memory an OS can provide.The stack will fall outside of the memory area, which might lead to an abnormal termination.Ĭons/drawbacks of using Heaps memory are:.Variable storage will be overwritten, which sometimes leads to undefined behavior of the function or program.Creating too many objects on the stack can increase the risk of stack overflow.Heap can be implemented using array and trees.Ĭons/Drawbacks of using Stack memory are: Memory is allocated in a contiguous block.Īutomatically done by compiler instructions.ĭoes not require to de-allocate variables.Ī stack can be implemented in 3 ways simple array based, using dynamic memory, and Linked list based. It allows you to access variables globally.ĭoes not have a specific limit on memory size. Memory can become fragmented as blocks of memory first allocated and then freed. Space managed efficiently by OS so memory will never become fragmented. Stack allocation and deallocation are done by compiler instructions whereas Heap allocation and deallocation is done by the programmer.Stack doesn’t require to de-allocate variables whereas in Heap de-allocation is needed.Stack memory is allocated in a contiguous block whereas Heap memory is allocated in any random order.