C program for Circular Queue

This is a C program for Circular Queue which includes insertion, Deletion, and Display of circular queue.

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#include<stdio.h> #include<conio.h> #include<string.h> #define max 11 int f=-1,r=-1,que[max]; int insert(int); int qdel(); int qdisplay(); void main() { int c,y; char k; clrscr(); do{ printf("\n\t\t*****ENTERUR CHOICE FOR CIRCULAR QUEUE*****\n"); printf("\n1)INSERT\n2)DELETE\n3)DISPLAY\n"); scanf("%d",&c); switch(c) { case 1: printf("\nENTER THE NUMBER"); scanf("%d",&y); insert(y); break; case 2: y=qdel(); printf("\nDELETED ELEMENT IS %d",y); break; case 3: printf("\n\t\tQUUE ELEMENTS ARE:\n"); qdisplay(); break; default : printf("\nWRONG CHOICE"); } printf("\n\nDO U WANT TO CONTINUE:(Y/N)"); k=getch(); } while(k=='y'||k=='Y'); } //Queue instertion int insert(int x) { if((r==max-1&&f==0)||r==f-1) { printf("\nQUEUE OVERFLOW DELETE SOME ELEMENT FROM FRONT"); return 0; } else { if(r==max-1) { r=0; } else { r++; } que[r]=x; } if(f==-1) { f++; } return 0; } //QUEUE DELETION int qdel() { int x; if(f==-1) { printf("\nQueue Underflow\n"); return 0; } x=que[f]; if(f==r) { f=-1; r=-1; return(x); } else if(f==max-1) { f=0; return(x); } else { f++; return(x); } } //QUEUE DISPLAY int qdisplay() { int i; if (f==-1) { printf("\nqueue is empty\n"); return 0; } else { if(r<f) { for(i=f;i<=max-1;i++) printf("%d ",que[i]); for(i=0;i<=r;i++) printf("%d ",que[i]); } else { for(i=f;i<=r;i++) printf("%d ",que[i]); } } return 0; }

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