Queue Operations using C Language

 

Write a program to Queue Operations using C Language to implement the following functions :

• Create Queue
• Delete Queue
• Display Queue
• Delete Queue

Queue Operations using C Language Code

#include  
 #include  
 #include  
 typedef struct queue  
 {  
 char name[20];  
 char diesease[50];  
 struct add  
 {  
 int hno;  
 int sno;  
 char city[20];  
 }add;  
 struct queue * link;  
 }queue;  
 typedef struct prior  
 {  
 queue * front;  
 queue * rear;  
 int priority;  
 struct prior * next;  
 }prior;  
 prior *create();  
 prior *delet(prior *);  
 void display(queue *,int *);  
 void alloc(queue *);  
 prior *freeall(prior *);  
 void main()  
 {  
 int ch,ch1,temp;  
 prior *t,*f=NULL;  
 do  
 {  
 clrscr();  
 printf("\n\t1.CREATE\n\t2.DELETE\n\t3.DISPLAY\n\t4.EXIT\n\tENTER UR CHOICE:");  
 scanf("%d",&ch);  
 switch(ch)  
 {  
 case 1: if(f!=NULL)  
 f=freeall(f);  
 printf("\nCREATE");  
 f=create();  
 break;  
 case 2:  
 if(f==NULL)  
 printf("FIRST CREATE !!!!!");  
 else  
 {  
 printf("\nDELETE");  
 f=delet(f);  
 }  
 getch();  
 break;  
 case 3:  
 if(f==NULL)  
 printf("FIRST CREATE !!!!!");  
 else  
 {  
 do  
 {  
 clrscr();  
 printf("\n\tDISPLAY\n\t1.BY CATEGORY\n\t2.ALL\n\t3.EXIT\n\tENTER UR CHOICE");  
 scanf("%d",&ch1);  
 switch(ch1)  
 {  
 case 1:  
 printf("\nENTER THE CATEGORY:\n1.SERIOUS\n2.NON-SERIOUS\n3.GENERAL");  
 scanf("%d",&ch);  
 temp=1;  
 t=f;  
 clrscr();  
 while(t!=NULL)  
 {  
 if(t->priority==ch)  
 break;  
 t=t->next;  
 }  
 if(t!=NULL)  
 display(t->front,&temp);  
 else  
 printf("NOT FOUND");  
 getch();  
 break;  
 case 2:  
 t=f;  
 temp=1;  
 clrscr();  
 while(t!=NULL)  
 {  
 display(t->front,&temp);  
 t=t->next;  
 }  
 getch();  
 break;  
 case 3:  
 break;  
 default:printf("\nINVALID CHOICE");  
 }  
 }while(ch1!=3);  
 }  
 getch();  
 break;  
 case 4:  
 break;  
 default:printf("\nINVALID CHOICE");  
 }  
 }while(ch!=4);  
 getch();  
 }  
 prior * create()  
 {  
 int p;  
 prior *f=NULL,*nw1,*t;  
 queue *nw;  
 do  
 {  
 nw=(queue *)malloc(sizeof(queue));  
 nw->link=NULL;  
 alloc(nw);  
 printf("\nGIVE THE PRIORITY TO THIS PATIENT:");  
 while(1)  
 {  
 scanf("%d",&p);  
 if(p>0&&p<4)  
 break;  
 else  
 printf("INVALID PRIORITY");  
 }  
 if(f==NULL)  
 {  
 nw1=(prior *)malloc(sizeof(prior));  
 nw1->next=NULL;  
 nw1->priority=p;  
 nw1->front=nw;  
 nw1->rear=nw;  
 f=nw1;  
 }  
 else  
 {  
 if(f->priority>p)  
 {  
 nw1=(prior *)malloc(sizeof(prior));  
 nw1->next=NULL;  
 nw1->priority=p;  
 nw1->front=nw;  
 nw1->rear=nw;  
 nw1->next=f;  
 f=nw1;  
 }  
 t=f;  
 while(p>=t->next->priority&&t->next!=NULL)  
 t=t->next;  
 if(p==t->priority)  
 {  
 t->rear->link=nw;  
 t->rear=nw;  
 }  
 else  
 {  
 nw1=(prior *)malloc(sizeof(prior));  
 nw1->next=NULL;  
 nw1->priority=p;  
 nw1->front=nw;  
 nw1->rear=nw;  
 nw1->next=t->next;  
 t->next=nw1;  
 }  
 }  
 printf("DO U WANT TO ENTER MORE:");  
 }while(getche()=='y'||getche()=='Y');  
 return f;  
 }  
 void alloc(queue *nw)  
 {  
 printf("\nENTER NAME:");  
 flushall();  
 gets(nw->name);  
 printf("\nENTER DIESEASE:");  
 flushall();  
 gets(nw->diesease);  
 printf("\nENTER H.NO:");  
 scanf("%d",&(nw->add.hno));  
 printf("\nENTER S.NO:");  
 scanf("%d",&(nw->add.sno));  
 printf("\nENTER CITY:");  
 flushall();  
 gets(nw->add.city);  
 }  
 void display(queue *t,int *temp)  
 {  
 while(t!=NULL)  
 {  
 printf("\n\nNAME:");  
 printf("%s",t->name);  
 printf("\nDIESEASE:");  
 printf("%s",t->diesease);  
 printf("\nADDRESS");  
 printf("\nHOUSE.NO:");  
 printf("%d",(t->add.hno));  
 printf("\nSTREET.NO:");  
 printf("%d",(t->add.sno));  
 printf("\nCITY:");  
 printf("%s",(t->add.city));  
 t=t->link;  
 getch();  
 }  
 }  
 prior *delet(prior *f)  
 {  
 prior *nw;  
 queue *q,*q1;  
 q=f->front;  
 if(q->link==NULL)  
 {  
 nw=f;  
 f=f->next;  
 free(nw);  
 }  
 else  
 f->front=q->link;  
 free(q);  
 printf("\nDATA is DELETED!!!!!!");  
 getch();  
 return f;  
 }  
 prior *freeall(prior *f)  
 {  
 prior *t;  
 queue *s,*r;  
 while(f!=NULL)  
 {  
 r=f->front;  
 while(r!=NULL)  
 {  
 s=r;  
 r=r->link;  
 free(s);  
 }  
 t=f;  
 f=f->next;  
 free(t);  
 }  
 return f;  
 }