Write a C Program to implement Linear Queue using array.

Program:-

#include<stdio.h>
#define MAX 10
int front=-1,rear=-1,q[MAX];

void ins()
{ int item;
 if(rear==MAX-1) { printf("Queue is full.\n"); }
 else
 { if(front==-1) { front=0; }
   printf("Enter item:"); scanf("%d",&item); rear=rear+1; q[rear]=item; 
 }
}

void del()
{ int item;
 if(front==-1||front>rear){ printf("Queue is empty.\n"); }
 else { item=q[front]; front=front+1; printf("%d is deleted.\n",item); }
  
}

void dis()
{ int i;
 if(front==-1||front>rear){ printf("Queue is empty.\n"); }
 else{ printf("Item's are:-\n"); for(i=front;i<=rear;i++){ printf("%d ",q[i]); } printf("\n");}
}

//This program is developed by thezenithcoder.blogspot.com

main()
{
 int val;
 while(val<4)
 {
  printf("\n1.INSERT\n2.DELETE\n3.DISPLAY\n4.EXIT\nEnter choice:");
  scanf("%d",&val);
  switch(val){
   case 1:ins(); break;
   case 2:del(); break;
   case 3:dis(); break;
  }
 }
 printf("Thank You for using.\n");
}

Output:-

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter choice:1
Enter item:10

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter choice:1
Enter item:20

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter choice:1
Enter item:30

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter choice:3
Item's are:-
10 20 30

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter choice:2
10 is deleted.

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter choice:3
Item's are:-
20 30

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter choice:1
Enter item:50

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter choice:3
Item's are:-
20 30 50

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter choice:4
Thank You for using.