Thread: Reversal of a Doubly Linked List !

Hi,

I was trying to reverse a list by swapping the previous and the next address of the current list. The logic seems to be right, but i cannot point as to where exactly the segmentation fault occurs.

Code:

#include <stdio.h>
#include <stdlib.h>
typedef struct Node
{
	int data;
	Node *next;
	Node *prev;
}Node;


Node* createNode(int data)
{
	Node *newNode = (Node *)malloc(sizeof(Node));
	newNode->data = data;
	newNode->next = NULL;
}
void BuildList(Node **root, int data)
{
	Node *temp = (*root);
	if(temp == NULL)
	{
		(*root) = createNode(data);
	}
	else
	{
		while(temp->next != NULL)
			{
				temp = temp->next;
			}
		Node *newNode = createNode(data);
		temp->next = newNode;
		newNode->prev = temp;
	}	
}

void reverseListSwap(Node **root)
{
	Node *current = (*root);
	Node *prev = NULL;
	Node *next = current->next;
	Node *loop = (*root);
	while(current->next != NULL)
	{
		Node *temp = current;
		temp->next = prev;
		temp->prev = next;
		prev = current;
		next = current->next;
		current = current->next;
	}
	current->next = prev;
	current->prev = NULL;
	(*root) = current;
}
int main()
{
	Node *root = NULL;
	BuildList(&root, 45);
	BuildList(&root, 46);
	BuildList(&root, 47);
	BuildList(&root, 48);
	BuildList(&root, 49);
	reverseListSwap(&root);
	printList(&root);
	return 0;
}