Re: please help with c program about queues

Hi everyone,

I am working on the piece of code below. It is supposed to allow the
user to insert 10 first names into a queue, then allow the user to
delete a name, and print the queue. I was able to compile the code,
run the program and enter the 10 first names in the queue. But then
the program "crashes": the program prints "error" infinitely many
times. I would appreciate if someone could help me identify the
problems.

Thanks a lot in advance for your help.

#include <stdio.h>
#define MAXNUM 10
#define MAXS 8

void insertq(void);
void deleteq(void);
void insertq(void);
void printq(void);

char q[MAXNUM][MAXS];
int h, t;
void main(void)
{
       char response[MAXS];
       h=-1;
       t=-1;
       printf("i/d/p/q");
       scanf("%s", response);
       while (response[0] != 'q' && response[0] != 'Q')
               switch(response[0]){
                       case 'i':
                               insertq();
                               break;
                       case 'd':
                               deleteq();
                               break;
                       case 'p':
                               printq();
                               break;
                       default:
                               printf("error input i/p/d/q");
                               break;
               }
       printf("i/p/d/q");
       scanf("%s", response);

}

void insertq(void)
{
       char response[MAXS];
       if (t-h+1 == MAXNUM)
               printf("overflow \n");
       else{
               printf("enter name");
               scanf("%s", response);
               if(h==-1){
                       h=0;
                       t=-1;
               }
       }

}

void printq(void)
{
       char response[MAXS];
       int j;
       printf("l or p");
       scanf("%s", response);

       if(response[0]=='l')
               for (j=h; j<=t; j++)
                               printf("%d %s \n", j, q[j]);
       if (response[0]=='p')
               for (j=h; j<=MAXNUM; j++)
                               printf("%d %s \n", j, q[j]);

}

void deleteq(void)
{
               if(h==-1)
                       printf("underflow \n");
               else
                       printf("servicing %s \n", q[h++]);
               if(h>t){
                       h=-1;
                       t=-1;
               } }