struct word_t* SortedMerge(struct word_t* one, struct word_t* two)
{
struct word_t* result = NULL;
if (one == NULL)
{
return(two);
}
else if (two == NULL)
{
return(one);
}
if (strcmp(one->word, two->word) < 0 )
{
result = one;
result->next = SortedMerge(one->next, two);
return(result);
}
else
{
result = two;
result->next = SortedMerge(one, two->next);
return(result);
}
return(result);
}
struct Link* SortedMerge(struct Link* a, struct Link* b)
{
struct Link* result = NULL;
/* Base cases */
if (a == NULL)
return(b);
else if (b==NULL)
return(a);
/* Pick either a or b, and recur */
if (
int_less( // returns true if alphabetical order
((Node*)(a))->p, // e.g. jane
((Node*)(b))->p // e.g. mike
)
)
{
result = a;
result->next = SortedMerge(a->next, b);
}
else
{
result = b;
result->next = SortedMerge(a, b->next);
}
return(result);
}
List_PersonPtr_Iterator SortedMerge(List_PersonPtr *list, List_PersonPtr_Iterator a, List_PersonPtr_Iterator b)
{
// A: begin, slow
// B: slow, end
if(a.node == NULL)
return b;
else if(b.node == NULL)
return a;
List_PersonPtr_Iterator result;
if(list->compare(a.deref(&a), b.deref(&b)))
{
List_PersonPtr_Iterator temp = a;
temp.inc(&temp);
result = a;
b = SortedMerge(list, temp, b);
result.node->next = b.node;
b.node->prev = result.node;
}
else
{
List_PersonPtr_Iterator temp = b;
temp.inc(&temp);
result = b;
a = SortedMerge(list, a , temp);
result.node->next = a.node;
a.node->prev = result.node;
}
return result;
}
//方法二: 递归
struct node *SortedMerge(struct node *ahead, struct node *bhead)
{
if (NULL == ahead)
{
return bhead;
}
if (NULL == bhead)
{
return ahead;
}
struct node *result = NULL;
if (ahead->data <= bhead->data)
{
result = ahead;
ahead = ahead->next;
}
else
{
result = bhead;
bhead = bhead->next;
}
result->next = SortedMerge(ahead, bhead);
return result;
}
/* Drier program to test above functions*/
int main()
{
/* Start with the empty list */
struct node *res = NULL;
struct node* a = NULL;
struct node* b = NULL;
/* Let us create two sorted linked lists to test
the functions
Created lists, a: 5->10->15, b: 2->3->20 */
push(&a, 15);
push(&a, 10);
push(&a, 5);
push(&b, 20);
push(&b, 3);
push(&b, 2);
printList(a);
printList(b);
/* Remove duplicates from linked list */
res = SortedMerge(a, b);
printf("Merged Linked List is: \n");
printList(res);
return 0;
}
int main(){
struct node *head1=NULL;
struct node *head2=NULL;
push(&head1,40);
push(&head1,30);
push(&head1,20);
push(&head1,10);
push(&head2,80);
push(&head2,70);
push(&head2,60);
push(&head2,50);
printList(head1);
printf("\n");
printList(head2);
printf("\n");
struct node *new_head = SortedMerge(head1,head2);
printList(new_head);
printf("\n");
printList(head1);
printf("\n");
printList(head2);
}
List_PersonPtr_Iterator node_sort(List_PersonPtr *list, List_PersonPtr_Iterator begin, List_PersonPtr_Iterator end)
{
List_PersonPtr_Iterator res1;
List_PersonPtr_Iterator res2;
if(begin.node == end.node)
{
begin.node->next = NULL;
return begin;
}
else
{
List_PersonPtr_Iterator slow = begin;
List_PersonPtr_Iterator fast = begin;
fast.inc(&fast);
while(!List_PersonPtr_Iterator_equal(fast,end))
{
fast.inc(&fast);
if(!List_PersonPtr_Iterator_equal(fast,end))
{
fast.inc(&fast);
slow.inc(&slow);
}
}
List_PersonPtr_Iterator slow_next = slow;
slow_next.inc(&slow_next);
slow.node->next = NULL;
res1 = node_sort(list, begin, slow);
res2 = node_sort(list, slow_next, end);
}
return SortedMerge(list, res1, res2);
}
void MergeSort(struct node** headRef)
{
struct node *head = *headRef;
struct node *head_front = NULL;
struct node *head_back = NULL;
if(head == NULL || head->next == NULL)
{
printf("return\n");
return;
}
FrontBackSplit(head, &head_front, &head_back);
print_linked_list("&head_front", &head_front);
MergeSort(&head_front);
print_linked_list("&head_back", &head_back);
MergeSort(&head_back);
*headRef = SortedMerge(head_front, head_back);
print_linked_list("headRef", headRef);
}
/*-------------Test Driver-----------*/
main(){
struct node* a = BuildOneTwo();
struct node* b = BuildOneTwoThree();
struct node* merged = SortedMerge(a,b);
struct node* temp = merged;
PrintList(temp);
}
/*
* @func: merge sort for link list
*/
struct node* MergeSortRecur(struct node* head){
if (head == NULL)
return NULL;
struct node* pfront = NULL;
struct node* pback = NULL;
FrontBackSplit(head, &pfront, &pback);
return SortedMerge(MergeSortRecur(pfront), MergeSortRecur(pback));
}
//SortedMerge() Using Recursion
//Merge() is one of those nice recursive problems where the recursive solution code is
//much cleaner than the iterative code. You probably wouldn't want to use the recursive
//version for production code however, because it will use stack space which is
//proportional to the length of the lists.
struct node* SortedMerge(struct node* a, struct node* b)
{
struct node* result = NULL;
// Base cases
if (a==NULL) return(b);
else if (b==NULL) return(a);
// Pick either a or b, and recur
if (a->data <= b->data) {
result = a;
a->next = SortedMerge(a->next, b);
}
else {
result = b;
b->next = SortedMerge(a, b->next);
}
return(result);
}
struct node* SortedMerge(struct node* a, struct node* b)
{
struct node* result = NULL;
if(a==NULL)
return(b);
else if(b==NULL)
return(a);
if(a->data <= b->data)
{
result = a;
result->next = SortedMerge(a->next,b);
}
else
{
result = b;
result->next = SortedMerge(a,b->next);
}
return(result);
}
main()
{
struct node* head=NULL;
struct node* a=BuildOneTwoThree();
struct node* b=BuildOneTwo();
head=SortedMerge(a,b);
while(head!=NULL){
printf("%d ",head->data);
head=head->next;
}
}
struct node* SortedMerge(struct node* a, struct node* b, int columnNumber[], char order[], int numberOfColumnsSort)
{
struct node* result = NULL;
/* Base cases */
if (a == NULL)
return(b);
else if (b==NULL)
return(a);
int i;
/* Pick either a or b, and recur */
for (i = 0; i<numberOfColumnsSort; ++i) {
int cNumber = columnNumber[i], flag = 0;
node *temp1, *temp2;
temp1 = a;
temp2 = b;
while (cNumber--) {
temp1 = temp1->row;
temp2 = temp2->row;
}
/*if(i == 1)
printf("**%d**\n", columnNumber[i]);*/
if ((strcmp(temp1->value, temp2->value) < 0 && order[0] == 'a') ||
(strcmp(temp1->value, temp2->value) > 0 && order[0] == 'd')) {
flag = 1;
result = a;
result->column = SortedMerge(a->column, b, columnNumber, order, numberOfColumnsSort);
}
else if((strcmp(temp1->value, temp2->value) == 0)) {
continue;
}
else {
flag = 1;
result = b;
result->column = SortedMerge(a, b->column, columnNumber, order, numberOfColumnsSort);
}
if(flag == 1)
break;
}
return(result);
}
ListNode* MergeSortRecur(ListNode* head){
if (head == NULL)
return NULL;
else if (head->next == NULL)
return head;
ListNode* pfront = NULL;
ListNode* pback = NULL;
FrontBackSplit(head, &pfront, &pback);
return SortedMerge(MergeSortRecur(pfront), MergeSortRecur(pback));
}
//better code...
void MergeSort(struct node** headRef) {
struct node* head = *headRef;
struct node* a;
struct node* b;
// Base case -- length 0 or 1
if ((head == NULL) || (head->next == NULL)) {
return;
}
FrontBackSplit(head, &a, &b); //
MergeSort(&a); //
MergeSort(&b);
*headRef = SortedMerge(a, b); //
}
// 15 — MergeSort()
void MergeSort(struct node** headRef) {
struct node* head = *headRef;
struct node* a;
struct node* b;
// Base case -- length 0 or 1
if ((head == NULL) || (head->next == NULL)) {
return;
}
FrontBackSplit(head, &a, &b); // Split head into 'a' and 'b' sublists
// We could just as well use AlternatingSplit()
MergeSort(&a); // Recursively sort the sublists
MergeSort(&b);
*headRef = SortedMerge(a, b); // answer = merge the two sorted lists together
}
ALinkList::AListNode *SortedMerge(ALinkList::AListNode *node1, ALinkList::AListNode *node2)
{
ALinkList::AListNode *result = NULL;
if(!node1)
return node2;
if(!node2)
return node1;
if(node1->data < node2->data)
{
result = node1;
result->Next = SortedMerge(node1->Next, node2);
}
else
{
result = node2;
result->Next = SortedMerge(node1, node2->Next);
}
return result;
}
ALinkList::AListNode * ALinkList::ZipMerge(AListNode *node1, AListNode *node2, bool bSwitch)
{
ALinkList::AListNode *result = NULL;
if(!node1)
return node2;
if(!node2)
return node1;
if(bSwitch)
{
result = node1;
result->Next = SortedMerge(node1->Next, node2);
bSwitch = false;
}
else
{
result = node2;
result->Next = SortedMerge(node1, node2->Next);
bSwitch = true;
}
return result;
}
struct node* SortedMerge(struct node *first, struct node *second)
{
struct node *result;
if(!first)
return second;
if(!second)
return first;
if(first->data < second->data)
{
result = first;
result->next = SortedMerge(first->next, second);
}
if(second->data < first->data)
{
result = second;
result->next = SortedMerge(first, second->next);
}
return result;
}
/* See http://geeksforgeeks.org/?p=3622 for details of this
function */
struct node* SortedMerge(struct node* a, struct node* b)
{
struct node* result = NULL;
/* Base cases */
if (a == NULL)
return (b);
else if (b==NULL)
return (a);
/* Pick either a or b, and recur */
if (a->data <= b->data)
{
result = a;
result->arbit = SortedMerge(a->arbit, b);
}
else
{
result = b;
result->arbit = SortedMerge(a, b->arbit);
}
return (result);
}
void MergeSort(struct word_t** headref)
{
struct word_t* one;
struct word_t* two;
struct word_t* head= *headref;
if (head == NULL || head->next == NULL)
{
return;
}
Split(head, &one, &two);
MergeSort(&one);
MergeSort(&two);
*headref = SortedMerge(one, two);
}
int main()
{
struct node *Node=NULL, *ptr=NULL;
struct node *start=NULL,*start1=NULL,*start2=NULL;
char ch;
do
{
ptr=Node;
Node=NewNode();
printf("\nEnter data :");
scanf("%d",&Node->data);
if(start1==NULL)
start1=Node;
else
ptr->next=Node;
printf("Do you want to continue(Y/N)");
}while(toupper((ch=getch()))!='N');
printf("\nComplete Linked list:\n");
PrintList(start1);
do
{
ptr=Node;
Node=NewNode();
printf("\nEnter data :");
scanf("%d",&Node->data);
if(start2==NULL)
start2=Node;
else
ptr->next=Node;
printf("Do you want to continue(Y/N)");
}while(toupper((ch=getch()))!='N');
printf("\nComplete Linked list:\n");
PrintList(start2);
start=SortedMerge(start1,start2);
printf("\n\nMerged Linked list:\n");
PrintList(start);
return 0;
}
void FileIconCollection::MergeSort(FileIcon *&headRef)
// sorts the linked list by changing next pointers (not data)
{
// Base case -- length 0 or 1
if (!headRef || !headRef->pNext) return;
// Split head into 'a' and 'b' sublists
FileIcon *a, *b;
FrontBackSplit(headRef, a, b);
// Recursively sort the sublists
MergeSort(a);
MergeSort(b);
// Merge the two sorted lists together
headRef = SortedMerge(a, b);
}
void MergeSort(struct node** headRef)
{
struct node* head = *headRef;
struct node* a;
struct node* b;
if((head == NULL) || (head->next == NULL))
{
return;
}
FrontBackSplit(head, &a, &b);
MergeSort(&a);
MergeSort(&b);
*headRef = SortedMerge(a,b);
}
int main() {
struct node *a = NULL;
SortedInsert2(&a, MakeNode(1));
SortedInsert2(&a, MakeNode(4));
SortedInsert2(&a, MakeNode(10));
struct node *b = NULL;
SortedInsert2(&b, MakeNode(3));
SortedInsert2(&b, MakeNode(9));
SortedInsert2(&b, MakeNode(21));
printf("a: "); PrintList(a);
printf("b: "); PrintList(b);
struct node *merged_and_sorted = SortedMerge(a, b);
printf("merged_and_sorted: "); PrintList(merged_and_sorted);
printf("a: "); PrintList(a);
printf("b: "); PrintList(b);
return 0;
}
/* sorts the linked list formed by arbit pointers
(does not change next pointer or data) */
void MergeSort(struct node** headRef)
{
struct node* head = *headRef;
struct node* a, *b;
/* Base case -- length 0 or 1 */
if ((head == NULL) || (head->arbit == NULL))
return;
/* Split head into 'a' and 'b' sublists */
FrontBackSplit(head, &a, &b);
/* Recursively sort the sublists */
MergeSort(&a);
MergeSort(&b);
/* answer = merge the two sorted lists together */
*headRef = SortedMerge(a, b);
}
/* sorts the linked list by changing next pointers (not data) */
void MergeSort(struct node** headRef, int columnNumber[], char order[], int numberOfColumnsSort)
{
struct node* head = *headRef;
struct node* a;
struct node* b;
/* Base case -- length 0 or 1 */
if ((head == NULL) || (head->column == NULL))
{
return;
}
/* Split head into 'a' and 'b' sublists */
FrontBackSplit(head, &a, &b);
/* Recursively sort the sublists */
MergeSort(&a, columnNumber, order, numberOfColumnsSort);
MergeSort(&b, columnNumber, order, numberOfColumnsSort);
/* answer = merge the two sorted lists together */
*headRef = SortedMerge(a, b, columnNumber, order, numberOfColumnsSort);
}
/* sorts the linked list by changing next pointers (not data) */
void MergeSort(struct Link** headRef)
{
struct Link* head = *headRef; // deref that pointer to get the address of sentinel link
struct Link* a;
struct Link* b;
//printf("%s is the head node's name\n", ((Node*)(head))->p->name);
//printf("%s is the head.next node's name\n", ((Node*)(head->next))->p->name);
//printf("%s is the head.next node's name\n", ((Node*)(head))->p->name);
// the above works b.c. address of head is address of head->next
//printf("%s is the head.prev node's name field====================\n", ((Node*)(head->prev))->p->name);
// this last stmt designed to fail: it should point to sentinel, which has no data
//1) If head is NULL or there is only one element
//in the Linked List, then return.
// Base case -- length 0 or 1
if ((head == NULL) || (head->next == NULL))
{
return;
}
//2) Else divide the linked list into two halves.
// a and b are two halves
/* Split head into 'a' and 'b' sublists
--a and b are empty when passed to FrontBackSplit,
and get their addresses populated when in that function.*/
printf("calling FrontBackSplit(head, &a, &b); \n");
FrontBackSplit(head, &a, &b);
//printf("calling MergeSort(&a); \n");
// Recursively sort the sublists
MergeSort(&a);
//printf("calling MergeSort(&b); \n");
MergeSort(&b);
// merge the two sorted lists together
*headRef = SortedMerge(a, b);
}
