Thread: bus error

what causes the bus error in the hashtable implementation file?

Code:

#include "Hashtable.h"

// Enter your implementation here
Hashtable::Hashtable(int m_that){
m = m_that;
//if (!T.empty()){
for(int j=0;j<m;j++)
T[j] = -1;
//}
}

// The primary hashing formula
int Hashtable::h1(int k){
  return k%m;
}

// The secondary hashing formula
int Hashtable::h2(int k){
  return 1+(k % (m-1));
}

// The overall (combined) hashing formula
int Hashtable::h(int k,int i){

  int index;
  while(i<m){
  index = (h1(k) + i*h2(k))%m;
  if(T[index] != -1)		  //occupied slot
  i++;
  if(T[index] == -1)		  //empty slot
  //if(index == m)
  //T[index-1] = k;
  //else
  T[index] = k ;  // Insert value 'k' into index = h1(k) in vector T
  return index;		//insertion ok, double hashing, call double hash
  }
  
  for(int j=0;j<T.size();j++){
  if (T[j] == k)
  return -2;  // If 'k' is already exist in the table
  if(i==m)				// else if vector T is full, all -1 slots filled up
  return -1;             //this method returns -1. No change to vector T
  }  
  }
	
int Hashtable::Hash_Insert(int k){
  int i=0;
  return h(k,i);  	
  }
			  
int Hashtable::Hash_Search(int k){

if(!T.empty()){
for(int j=0;j<T.size();j++){
if (T[j] == k)
return j;   // Returns the index of item 'k' in vector T
if (T[j] != k)
return -1;  // Returns -1 if item 'k' is not found
}
}
}

Your search is broken to start with ...

Code:

int Hashtable::Hash_Search(int k)
{
    if (!T.empty())
    {
        for(int j=0;j<T.size();j++)
        {
            if (T[j] == k)
                return j;   // Returns the index of item 'k' in vector T
            if (T[j] != k)
                return -1;  // Returns -1 if item 'k' is not found
        }
    }
}

Should be

Code:

int Hashtable::Hash_Search(int k)
{
    if (!T.empty())
    {
        for(int j=0;j<T.size();j++)
        {
            if (T[j] == k)
                return j;   // Returns the index of item 'k' in vector T
        }
    }

    return -1;  // Returns -1 if item 'k' is not found
}

yeah u were right. thanks for pointing out tt error...