C / C++ / MFC

manoharbalu wrote:

When I try to write the above object 'oTest' to a simple file using fwrite and CFile and then try to read using fread, I am getting bad pointer in oTest.str

numStruct* deleteNode(numStruct** firstNode, numStruct* nodeToDelete)

numStruct* t = anchorNode;
...
deleteNode(anchorNode, t);

int main(void)
{
    numStruct* anchorNode = NULL;
    numStruct* newNode = NULL;    
    AddSongs(anchorNode, newNode);
 
    system("PAUSE");
}

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

struct numberNode {
	int number;
	struct numberNode *Next;
};

typedef struct numberNode numStruct;

numStruct *createSong(int numbers)
{
	numStruct *newSong = (numStruct *)malloc(sizeof(numStruct));
	if (newSong)
	{
		newSong->number = numbers;
		newSong->Next = NULL;
	}
	return newSong;
}

void insertAtEnd(numStruct **firstNode, numStruct *newNode)
{
	numStruct *currNode = *firstNode;

	// if the linked list is empty
	// should put the new node as the first
	if (!currNode)
	{
		*firstNode = newNode;
		newNode->Next = NULL;
	}
	else
	{
		while (currNode->Next)	// problem at the second loop
		{
			currNode = currNode->Next;
		}

		currNode->Next = newNode;
		newNode->Next = NULL;
	}
	printf("\n\n");
}

numStruct *AddSongs(numStruct **anchorNode, numStruct *newNode)
{
	int count = 0;
	int numbers;

	printf("\nPlease enter numbers and at the end enter -999\n");

	do
	{
		count++;
		//flushall();
		fflush(stdin);
		numbers = 0;

		printf("\n\n%d.\n\nnumber: ", count);
		scanf("%d", &numbers);

		if (numbers != -999)
		{
			newNode = createSong(numbers);
			insertAtEnd(anchorNode, newNode);
		}
	}
	while (numbers != -999);
	printf("\n\n");
	return NULL;
}

void printList(numStruct *firstNode)
{
	numStruct *currSong = firstNode;
	printf("\n\n-------------------------------------\n");
	while (currSong)
	{
		printf("number= %d \n", currSong->number);
		currSong = currSong->Next;
	}
	printf("-------------------------------------\n\n");
	printf("\n\n");
}

int main(void)
{
	numStruct *anchorNode = NULL;
	numStruct *newNode = NULL;
	AddSongs(&anchorNode, newNode);
	printList(anchorNode);

	system("PAUSE");
}

void deleteNode(numStruct **firstNode, numStruct *nodeToDelete)
{
	numStruct *temp = NULL;

	if (!*firstNode)
		return;	//Empty list

	// Special case the node we must delete is the first one
	if (*firstNode == nodeToDelete)
	{
		temp = *firstNode;
		*firstNode = (*firstNode)->Next;
		free(temp);
		return;
	}

	for (numStruct * currNode = *firstNode; currNode->Next; currNode = currNode->Next)
	{
		if (nodeToDelete == currNode->Next)
		{
			temp = currNode->Next;
			currNode->Next = (currNode->Next)->Next;
			free(temp);
			return;
		}
	}
}

void RemoveNodes(numStruct **anchorNode)
{
	numStruct *t = *anchorNode;
	int arr[50] = {0};
	int spot = 0;

	printf("Please enter all the numbers you want to delete and end it with - 999 \n");

	for (spot=0; spot < 50; spot++)
	{
		fflush (stdin);
		scanf("%d", &arr[spot]);
		if (arr[spot] == -999)
			break;
	}

	if (spot >= 50)
		spot--;

	for (int i = 0; i < spot; i++, t = *anchorNode)
	{
		while (t != NULL)
		{
			if (t->number == arr[i])
			{
				deleteNode(anchorNode, t);
				break;
			}
			t = t->Next;
		}
	}
}

int main(void)
{
	numStruct *anchorNode = NULL;
	numStruct *newNode = NULL;
	AddSongs(&anchorNode, newNode);
	printList(anchorNode);

	RemoveNodes(&anchorNode);
	printList(anchorNode);

	system("PAUSE");
}

a random user wrote:

the problem is that it doesnt really delete it