Create queue.c

C/queue.c

@@ -0,0 +1,108 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+struct stack
+{
+  int size;
+  int top;
+  int *s;
+}s1,s2;
+
+void push(struct stack *st,int x)
+{
+    st->top++;
+    st->s[st->top]=x;
+
+}
+
+int pop(struct stack *st)
+{
+    int x;
+    x=st->s[st->top];
+    st->top--;
+    return x;
+}
+
+int isEmpty(struct stack st)
+{
+    if(st.top==0)
+        return 1;
+    else
+        return 0;
+}
+
+void enqueue(int x)
+{
+    if(!(s1.top+s2.top==s1.size))
+        push(&s1,x);
+    else
+        printf("Queue is full\n");
+}
+
+int dequeue()
+{
+    int x=-1;
+    if(isEmpty(s2))
+    {
+        if(isEmpty(s1))
+        {
+            printf("Queue is empty\n");
+            return x;
+        }
+        else
+        {
+            while(!(isEmpty(s1)))
+                push(&s2,pop(&s1));
+        }
+    }
+    return pop(&s2);
+}
+
+void display()
+{   int i,t;
+    if(!(isEmpty(s2)))
+    {
+        t=s2.top;
+        for(i=t;i>0;i--)
+            printf("%d  ",s2.s[i]);
+    }
+    if(!(isEmpty(s1)))
+    {
+        t=s1.top;
+        for(i=1;i<=t;i++)
+            printf("%d  ",s1.s[i]);
+    }
+    printf("\n");
+}
+
+int main()
+{
+    printf("Enter the size of the Queue:");
+    scanf("%d",&s1.size);
+    s2.size=s1.size;
+    s1.top=0;
+    s2.top=0;
+    s1.s = (int *) malloc(s1.size * sizeof(int));
+    s2.s = (int *) malloc(s1.size * sizeof(int));
+
+    int f = 0, a;
+    char ch = 'y';
+    while (ch == 'y'||ch == 'Y') {
+        printf("Enter ur choice\t 1.Add to queue\t 2.Remove from queue\t 3.Display\t 4.Exit\t: ");
+        scanf("%d", &f);
+        switch(f) {
+            case 1 : printf("Enter the element to be added to queue : ");
+                     scanf("%d", &a);
+                     enqueue(a);
+                     break;
+            case 2 : dequeue();
+                     break;
+            case 3 : display();
+                     break;
+            case 4 : ch=a;
+                     break;
+            default : printf("Invalid\n");
+                      break;
+        }
+    }
+}