im solving a problem in linked list.how to check loop inside a linked list.
i ve done implentation. always it goes without any error. but sometimes it encounters
segmentation error. i dont find wny error or warning other than that.please try to help me figure out

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

/*
 * structure for the linkedlist node
 */
typedef struct node *ptr;
typedef ptr list;
typedef struct listnode *hcell;
typedef hcell cell;
typedef struct hashtable *hashtbl;
struct node
{
int ele;	//element
struct node *next;//next pointer
};
/*
 * opening the file for input
 */
void Hasloop(int);
struct listnode
{
unsigned int lielement;
 struct listnode *nextele;
};

struct hashtable
{
cell *lists;
int tablesize;
};
list l;
hashtbl h;
int num;


int nextPrime(int n)
{
int m=0,flag=0,i=0;
while(m==0)
{
flag=0;
for(i=2;i<n;i++)
{
 if(n%i==0)
 {
  flag=1;
  n++;
  break;
 }
}
if(flag==0)
{
m++;
}
}
return n;
}

void initialize()
{
int tsize=15,i=0;

h=malloc(sizeof(struct hashtable));

h->tablesize=nextPrime(15);
h->lists=malloc(sizeof(struct listnode)*15);
for(i=0;i<tsize;i++)
{
h->lists[i]=malloc(sizeof(struct listnode));
h->lists[i]->nextele=NULL;
}

}

int hash(unsigned int e)
{
 int i=0;
i=e%h->tablesize;
return i;  
}

cell find(int e)
{
cell pc=h->lists[hash(e)];
cell lc=pc->nextele;
 while(lc!=NULL && lc->lielement!=e)
 lc=lc->nextele;
 return lc;
}

void insert( unsigned int l)
{
  
  int i;
  int emsg=0;
  cell pos,newcell,lc,gc,cc;
  lc=h->lists[hash(l)];
  if(lc->lielement!=l || lc->lielement==0)
  { 
    lc->lielement=l;
    lc->nextele=NULL;
  }
  else
  { 
  printf("Came here");
  emsg=1;
  Hasloop(emsg);
  }
}

void Createlinklist()
{
FILE *fp;
int *f;
fp=fopen("input.txt","r");
int i=0,e=0;
fscanf(fp,"%d",&num);
list p,o,k;
while(num!=i)
{
  fscanf(fp,"%d",&e);
  if(i==0)
  {
    l=malloc(sizeof(struct node));
    l->ele=e;
    l->next=NULL;
    p=l;
   }
  else
  {
   p->next=malloc(sizeof(struct node));
   p->next->ele=e;
   p->next->next=NULL;
   p=p->next;
  }
  i++;
}

o=l;
k=l;
while(k->next!=NULL)
k=k->next;
while(o->next!=NULL && o->ele!=65)
o=o->next;
k->next=o;

}

void Hasloop(int e)
{
list o,k;
o=l;
k=l;
if(e==1)
{
printf("Loop exists ......Terminating program\t\t\t[\tOK\t]\t\n");
exit(0);
}
else if(k->next==o)
{
 printf("Loop exists between start and end node ......Terminating program\t\t\t[\tOK\t]\n");
 exit(0);
}

}

void Displaylist()
{
  list p;
  cell gc;
  p=l;
  int i=0,j=0;
  printf("\nStarting address:\n");
  while(p!=NULL)
  {
    printf("[%d]==>%u\n",p->ele,(unsigned int)&p->ele);
    i++;
    p=p->next;
    if(i>5)
      break;
  }
  i=0;
  p=l;
  printf("\n\n");
  printf("\nNext pointer address:\n");
  while(p!=NULL)   
  { 
    if(i==0)
    insert((unsigned int)&p->ele);
    if(j<num)
    insert((unsigned int)p->next);  
    printf("[%d]==>%u\n",p->ele,(unsigned int)p->next);
    p=p->next;
    i++;
    j++;
    if(i>25)
      break;
  }
  i=0;
   while(i<15)
  {
    gc=h->lists[i];
    printf("%d\n",gc->lielement);
    i++;    
  }
}

void main()
{
  initialize();
  Createlinklist();
  //hasloop();
  Displaylist();
}

but sometimes it encounters segmentation error.

On what part does the segmentation fault occur?

Edited 4 Years Ago by zeroliken: n/a

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