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Bus Error

snazziosity (21)
I keep getting a bus error when I run the program with its client (robot.cpp). Something to do with curptr -> info in FillBuckets, I think, or possibly the typedef Pebble. Also, I am having trouble coding TrashBuckets.

Please note that the only file I am allowed to edit is buckets.cpp.

buckets.cpp
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class Buckets;
#include "buckets.h"
#include <cstdlib>
#include <iostream>
using namespace std;

typedef Pebble ItemType;

struct NodeType
{
	Pebble info;
	NodeType* next;
};

struct BuckStuff
{
	NodeType* firstptr;
	int num;
};

//@gets a number of buckets for the robot
//@pre number is assigned the desired number of buckets
//@post number buckets are placed in front of the robot
//@param number is the number of buckets desired
//@usage  b.GetBuckets(5);
void Buckets::SetUpBuckets(int number)
{
	buckets = new(nothrow) BuckStuff;
	buckets -> num = number;
	buckets -> firstptr = NULL;
	if (number > 0)
	{
		buckets -> firstptr = new(nothrow) NodeType;
		NodeType* curptr;
		curptr = buckets -> firstptr;
		curptr -> next = NULL;
		for (int i; i < number - 1; i++)
		{
			curptr -> next = new(nothrow) NodeType;
			curptr = curptr -> next;
			curptr -> next = NULL;
		}
	}
}

//@fills all of the buckets with pebbles
//@pre buckets are placed in front of the robot
//@post one colored pebble is placed in each bucket
//@     according to the user's input
//@usage   b.FillBuckets();
void Buckets::FillBuckets()
{
	char color;
	NodeType* curptr;

	curptr = buckets -> firstptr;
	cout << "Enter R for red, W for white, B for Blue. " << endl;
	for(int i = 0; i < buckets -> num; i++)
	{
		cout << "Enter color for bucket " << i + 1 << " -> ";
		cin >> color;
		if(color == 'R' || color == 'r')
			curptr -> info = RED;
		else if(color == 'W' || color == 'w')
			curptr -> info = WHITE;
		else
			curptr -> info = BLUE;
		curptr = curptr -> next;
		cout << curptr -> info;
	}
}

//@robot uses its eye to view the color of the pebble
//@pre i is the position of the bucket
//@    positions of the buckets are labeled 0, 1, 2, ....
//@post the color of the pebble is returned
//@param i
//@return the color of the pebble
//@usage  pebble = b.GetColor(2);
Pebble Buckets::GetColor(int i)
{
	NodeType* curptr = buckets -> firstptr;
	for(int k=0; k< i; k++)
		curptr = curptr -> next;
	return curptr -> info;
}

//@robot swaps the pebbles in two buckets with its arms
//@pre  i and j are the positions of the two buckets
//@     buckets are given positions 0, 1, 2, 3,...
//@post the pebbles in buckets i and j are swapped
//@param i
//@param j
//@usage    b.Swap(i,j);
void Buckets::Swap (int i, int j)
{
	int temp;
	temp = i;
	i = j;
	j = temp;
}

//@all of the buckets are thrown in the trash
//@pre  there are buckets placed before the robot
//@post there are no buckets placed before the robot
//@usage   b.TrashBuckets();
/*void Buckets::TrashBuckets()
{
   NodeType* delptr;

   while (buckets -> firstptr != NULL)
   {
      delptr = buckets;
      buckets = buckets -> firstptr;
      delptr -> next = NULL;
      delete delptr;
   }
}*/

//@counts the number of buckets placed before the robot
//@pre   there are buckets
//@post  returns the number of buckets
//@usage   num = b.GetNum();
int Buckets::GetNumber()
{
	return buckets -> num;
}


buckets.h - NOTE - CANNOT EDIT THIS.
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enum Pebble {RED, WHITE, BLUE};
struct BuckStuff;

class Buckets
{
public:
   //@gets a number of buckets for the robot
   //@usage  b.GetBuckets(5);
   void SetUpBuckets(int number);
   
   //@fills all of the buckets with pebbles
   //@usage   b.FillBuckets();
   void FillBuckets();
   
   //@robot uses its eye to view the color of the pebble
   //@usage  pebble = b.GetColor(2);
   Pebble GetColor(int i);
   
   //@robot swaps the pebbles in two buckets with its arms
   //@usage    b.Swap(i,j);
   void Swap (int i, int j);
   
   //@all of the buckets are thrown in the trash
   //@usage   b.TrashBuckets();
   //void TrashBuckets();
   
   //@counts the number of buckets placed before the robot
   //@usage   num = b.GetNum();
   int GetNumber();
private:
   BuckStuff* buckets;
};


robot.cpp - NOTE - CANNOT EDIT THIS
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#include "buckets.h"
#include <iostream>
using namespace std;


//@gets the number of buckets from the user
//@usage: num = getNumberOfBuckets();
int getNumberOfBuckets();

//@gets the answer to continue or not from the user
//@usage userSays = getUsersAnswer();
char getUsersAnswer();

//@prints the contents of the buckets
//@usage print(buckets);
void print(Buckets buckets);

//@sorts the pebbles into red section, white section, blue section
//@usage sort(buckets);
void sort(Buckets& buckets);

//@prints a number of newlines
//@usage  printNewLines(4);
void printNewLines(int num);

//@ checks that a bucket label exists
//@usage if (isOkBucket(label))
bool isOkBucket(Buckets buckets, int label);

//@prints a message if a nonexisting bucket is accessed
//@usage printBadBucketMessage(label);
void printBadBucketMessage(int label);

int main()
{
   Buckets buckets;
   char userSays;
   int number;
   
   userSays = 'y';
   printNewLines(3);
   while (userSays == 'y')
   {
      number = getNumberOfBuckets();
      buckets.SetUpBuckets(number);
      printNewLines(2);
      buckets.FillBuckets();
      cout << "I got here!" << endl;
      printNewLines(3);
      print(buckets);
      sort(buckets);
      printNewLines(3);
      print(buckets);
      //buckets.TrashBuckets();
      printNewLines(2);
      userSays = getUsersAnswer();
      printNewLines(2);
   }
   return 0;
}

//@gets the number of buckets from the user
//@usage: num = getNumberOfBuckets();
int getNumberOfBuckets()
{
   int number;
   cout << "Enter the number of buckets -> ";
   cin >> number;
   return number;
}

//@gets the answer to continue or not from the user
//@usage userSays = getUsersAnswer();
char getUsersAnswer()
{
   cout << "Do you want to run again <y> or <n>? ";
   char answer;
   cin >> answer;
   return answer;
}

//@prints the contents of the buckets
//@usage print(buckets);
void print(Buckets buckets)
{
   for (int i = 0; i < buckets.GetNumber(); i++)
   {
      if (buckets.GetColor(i) == RED)
         cout << i << " : " << "Red" << endl;
      else if (buckets.GetColor(i) == WHITE)
         cout << i << " : " << "White" << endl;
      else
         cout << i << " : " << "Blue" << endl;
   }
}

//@sorts the pebbles into red section, white section, blue section
//@usage sort(buckets);
void sort(Buckets& buckets)
{
   int lastRed = -1;
   int lastWhite = -1;
   int firstMixed = 0;
   while (firstMixed < buckets.GetNumber())
   {
      if (isOkBucket(buckets, firstMixed))
      {
         if (buckets.GetColor(firstMixed) == BLUE)
         {
            firstMixed++;
         } else if (buckets.GetColor(firstMixed) == WHITE)
         {
            lastWhite++;
            if (isOkBucket(buckets, lastWhite))
               buckets.Swap(lastWhite, firstMixed);
            else
               printBadBucketMessage(lastWhite);
            firstMixed++;
         } else 
         {
            lastWhite++;
            if (isOkBucket(buckets, lastWhite))
               buckets.Swap(lastWhite, firstMixed);
            else
               printBadBucketMessage(lastWhite);
            lastRed++;
            if (isOkBucket(buckets, lastRed))
               buckets.Swap(lastRed, lastWhite);
            else
               printBadBucketMessage(lastRed);
            firstMixed++;
         }
      } else {
         printBadBucketMessage(firstMixed);
      }
   }
}

//@prints a number of newlines
//@usage  printNewLines(4);
void printNewLines(int num)
{
   for (int i = 0; i < num; i++)
   {
      cout << endl;
   }
}

//@ checks that a bucket label exists
//@usage if (isOkBucket(label))
bool isOkBucket(Buckets buckets, int label)
{
   if (label >= 0 && label < buckets.GetNumber())
   {
      return true;
   } else {
      return false;
   }
}

//@prints a message if a nonexisting bucket is accessed
//@usage printBadBucketMessage(label);
void printBadBucketMessage(int label)
{
   cout << "bucket with label " << label << "does NOT exist!" << endl;
}


Any help would be appreciated, thanks!
Last edited on
kbw (9488)
In void Buckets::SetUpBuckets(int number), you have construct for (int i; i < number - 1; i++). i is uninitialised.
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