Add defintions for Message Queue

Message Queue(Circular Queue)/MessageQueue-definition.c

@@ -0,0 +1,95 @@
+#include "MessageQueue.h"
+
+int isFull(queue *q)
+{
+  if((q->rear == SIZE - 1 && q->front == 0) || (q->rear == q->front - 1))
+  {
+    return 1;
+  }
+  return 0;
+}
+
+int isEmpty(queue *q)
+{
+  if(q->front == -1)
+  {
+    return 1;
+  }
+  return 0;
+}
+
+void enqueue(queue *q, char message[100])
+{
+  if(!isFull(q))
+  {
+    if(q->front == -1)
+    {
+      q->front = q->rear = 0;
+      strcpy(q->arr[q->rear],message);
+    }
+    else if(q->rear == SIZE - 1 && q->front != 0)
+    {
+      q->rear = 0;
+      strcpy(q->arr[q->rear],message);
+    }
+    else
+    {
+      q->rear++;
+      strcpy(q->arr[q->rear],message);
+    }
+  }
+  else
+  {
+    printf("Queue Overflow.\n");
+  }
+}
+
+void dequeue(queue *q)
+{
+  if(q->front == -1)
+  {
+    printf("Queue Underflow\n");
+    return;
+  }
+    char data[100];
+    strcpy(data,q->arr[q->front]);
+    if(q->front == q->rear)
+    {
+      q->front = -1;
+      q->rear = -1;
+    }
+    else if(q->front == SIZE - 1 )
+    {
+      q->front = 0;
+    }
+    else
+    {
+      q->front++;
+    }
+    printf("Dequeued String: %s\n",data);
+}
+
+void display(queue *q)
+{
+  int i,j;
+  if(isEmpty(q))
+  {
+    printf("Queue is Empty\n");
+  }
+  else
+  {
+    if(q->rear >= q->front)
+    {
+      for(i = q->front; i <= q->rear; i++)
+        printf("%s\n",q->arr[i]);
+    }
+    else
+    {
+      for (i = q->front; i < SIZE; i++)
+            printf("%s\n", q->arr[i]);
+
+        for (i = 0; i <= q->rear; i++)
+            printf("%s\n", q->arr[i]);
+    }
+  }
+}