created circular queue implementation

circularqueue.c

@@ -0,0 +1,147 @@
+
+
+#include<stdio.h>
+#include<limits.h>
+
+int front=-1;
+int rear=-1;
+void enqueue(int * arr,int b,int size){
+int nexrear=(rear%(size-1));
+if(rear!=size-1)
+nexrear=nexrear+1;
+if(nexrear==front){
+    printf("queue is full");
+    return;
+}
+    else{
+        arr[nexrear]=b;
+        rear=nexrear;
+        if(front==-1)
+        front=0;
+    }
+}
+
+
+void print(int *arr,int size){
+
+    if (front == -1)
+    {
+        printf("\nQueue is Empty");
+        return;
+    }
+   printf("\n updated queue is :");
+    if (rear >= front)
+    {
+        for (int i = front; i <= rear; i++)
+            printf("%d ",arr[i]);
+    }
+    else
+    {
+        for (int i = front; i < size; i++)
+            printf("%d ", arr[i]);
+
+        for (int i = 0; i <= rear; i++)
+            printf("%d ", arr[i]);
+    }
+
+}
+
+int IsEmpty(){
+    if(front ==-1 || rear==-1)
+    return 1;
+    else return 0;
+}
+int isfull(int size){
+    int nexrear=(rear%(size-1));
+    if(rear!=size-1)
+    nexrear=nexrear+1;
+    if(nexrear==front){
+
+        return 1;
+    }
+else return 0;
+}
+
+void dequeue(int *arr,int size){
+
+printf("\n the dequeued element is %d",arr[front]);
+    arr[front]=INT_MIN;
+    if(front==rear){
+        front=-1;
+        rear=-1;
+    }
+    else{
+        int tempfront=front;
+        front=(front%(size-1));
+        if(tempfront!=size-1)
+        front=front+1;
+    }
+}
+
+
+
+int main(){
+
+
+    int arr[4];
+    for(int i=0;i<4;i++){
+        arr[i]=INT_MIN;
+    }
+    printf("press 0 to enqueue\n");
+    printf("press 1 to dequeue\n");
+    printf("press 2 to check if queue is empty\n");
+    printf("press 3 to check if queue is full\n");
+    printf("press ctrl+z to exit");
+while(1){
+    int a;
+    printf("\n Enter the choice");
+    scanf("%d",&a);
+
+    switch(a)
+    {
+        case 0:
+
+        if(isfull(4)){
+        printf("the queue is full");
+        break;
+        }
+        else{
+            printf("enter the element to enqueue");
+            int b;scanf("%d",&b);
+        enqueue(arr,b,4);
+        print(arr,4);
+        }
+        break;
+
+
+        case 1:
+
+        if(IsEmpty())
+        printf("the queue is empty");
+        else{
+            dequeue(arr,4);
+            print(arr,4);
+        }
+          break;
+
+          case 2:
+          if(IsEmpty())
+          printf("the queue is empty");
+          else
+          printf("the queue is not empty");
+          break;
+
+          case 3:
+          if(isfull(4))
+          printf("the queue is full");
+          else
+          printf("the queue is not full");
+          break;
+
+          default:
+          printf("enter the valid choice\n");
+          break;
+    }
+}
+}
+