C++: incorrect swapping of nodes in linked list
- by Dragon
I have 2 simple structures:
struct Address
{
char city[255];
};
typedef Address* AddressPtr;
struct Person
{
char fullName[255];
Address* address;
Person* next;
};
typedef Person* PersonPtr;
The Person structure forms the Linked list where new elements are added to the beginning of the list. What I want to do is to sort them by fullName. At first I tried to swap links, but I lost the beginning of the list and as a result my list was sorted partially. Then I decided to sort list by swapping the values of nodes. But I get strange results. For a list with names: Test3, Test2, Test1, I get Test3, Test3, Test3.
Here is my sorting code:
void sortByName(PersonPtr& head)
{
TaskPtr currentNode, nextNode;
for(currentNode = head; currentNode->next != NULL; currentNode = currentNode->next)
{
for(nextNode = currentNode->next; nextNode != NULL; nextNode = nextNode->next)
{
if(strcmp(currentNode->fullName, nextNode->fullName) > 0)
{
swapNodes(currentNode, nextNode);
}
}
}
}
void swapNodes(PersonPtr& node1, PersonPtr& node2)
{
PersonPtr temp_node = node2;
strcpy(node2->fullName, node1->fullName);
strcpy(node1->fullName, temp_node->fullName);
strcpy(node2->address->city, node1->address->city);
strcpy(node1->address->city, temp_node->address->city);
}
After the sorting completion, nodes values are a little bit strange.
UPDATED
This is how I swapped links
void swapNodes(PersonPtr& node1, PersonPtr& node2)
{
PersonPtr temp_person;
AddressPtr temp_address;
temp_person = node2;
node2 = node1;
node1 = temp_person;
temp_address = node2->address;
node2->address = node1->address;
node1->address = temp_address;
}
