Queue using Array

Implementation of queue using arrays and its functions.

Queue Structure :
struct Queue {
    int size;
    int front;
    int rear;
    int *data;
};
Creating a Queue Dynamically :
struct Queue *createQueue(int size) {
​
    // Allocating memory for queue
    struct Queue *queue;
    queue = (struct Queue *)malloc(sizeof(struct Queue));
    
    // Set size, front and rear
    queue -> size = size;
    queue -> front = -1;
    queue -> rear = -1;
    
    // Allocating memory for array
    queue -> data = (int *)malloc(size * sizeof(int));
    
    return queue;
​
}
Function to Check if Queue is Empty or Full :
int isEmpty(struct Queue *queue) {
    return queue -> front == queue -> rear;
}
​
int isFull(struct Queue *queuevoid display(struct Queue *queue) {
  return queue -> rear == queue -> size - 1;
}
En-queue Function :
void enqueue(struct Queue *queue, int data) {
​
    if (isFull(queue)) {
        printf("Queue overflow !\n");
        return;
    }
    queue -> rear++;
    queue -> data[queue -> rear] = data;
​
}
De-queue Function :
int dequeue(struct Queue *queue) {
​
    if (isEmpty(queue)) {
        printf("Queue underflow !\n");
        return -1;
    }
    queue -> front++;
    int deletedValue = queue -> data[queue -> front];
    return deletedValue;
​
}
Display Function :
void display(struct Queue *queue) {
​
    for (int i = queue -> front + 1; i <= queue -> rear; i++) {
        printf("%d\t", queue -> data[i]);
    }
    printf("\n");
​
}
Contributed by Nitin Ranganath

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Last modified 3yr ago