单链表合并

已知两个链表head1 和head2 各自有序，请把它们合并成一个链表依然有序。(保留所有结点，即便大小相同）

#include <stdio.h>

#include <stdlib.h>

typedef struct _Node{

int data;

_Node* next;

}Node, *LinkList;

bool CreateList(LinkList &head, const int *data, const int len)

{

Node *cur = NULL;

Node *next = NULL;

int i;

cur = (LinkList)malloc(sizeof(Node));

if(cur == NULL)

return false;

cur->data = data[0];

cur->next = NULL;

head = cur;

for(i=1; i<len; i++)

{

next = (LinkList)malloc(sizeof(Node));

if(next == NULL)

return false;

next->data = data[i];

next->next = NULL;

cur->next = next;

cur = cur->next;

}

return true;

}

void PrintList(LinkList head)

{

while(head != NULL)

{

printf(" %d", head->data);

head = head->next;

}

}

//一般合并

LinkList MergeList(LinkList head1, LinkList head2)

{

if (head1 == NULL)

return head2;

if (head2 == NULL)

return head1;

LinkList head = NULL;

LinkList p1 = NULL;

LinkList p2 = NULL;

if ( head1->data < head2->data )

{

head = head1;

p1 = head1->next;

p2 = head2;

}

else

{

head = head2;

p2 = head2->next;

p1 = head1;

}

LinkList cur = head;

while ( (p1!=NULL) && (p2!=NULL) )

{

if ( p1->data <= p2->data )

{

cur->next = p1;

cur = p1;

p1 = p1->next;

}

else

{

cur->next = p2;

cur = p2;

p2 = p2->next;

}

}

if ( p1 != NULL )

cur->next = p1;

if ( p2 != NULL )

cur->next = p2;

return head;

}

//递归合并

LinkList RMergeList(LinkList head1, LinkList head2)

{

if (head1 == NULL)

return head2;

if (head2 == NULL)

return head1;

LinkList head = NULL;

if (head1->data < head2->data)

{

head = head1;

head->next = RMergeList(head1->next, head2);

}

else

{

head = head2;

head->next = RMergeList(head1, head2->next);

}

return head;

}

void main( void )

{

int data1[] = {1, 2, 3, 5};

int len1 = sizeof(data1)/sizeof(int);

int data2[] = {2, 4, 6};

int len2 = sizeof(data2)/sizeof(int);

LinkList head;

LinkList head1;

LinkList head2;

if( !CreateList(head1, data1, len1) )

{

printf("创建链表失败！\n");

return;

}

if( !CreateList(head2, data2, len2) )

{

printf("创建链表失败！\n");

return;

}

printf("链表1：");

PrintList(head1);

printf("\n");

printf("链表2：");

PrintList(head2);

printf("\n");

head = MergeList(head1, head2);

printf("一般合并：");

PrintList(head);

printf("\n");

if( !CreateList(head1, data1, len1) )

{

printf("创建链表失败！\n");

return;

}

if( !CreateList(head2, data2, len2) )

{

printf("创建链表失败！\n");

return;

}

printf("链表1：");

PrintList(head1);

printf("\n");

printf("链表2：");

PrintList(head2);

printf("\n");

head = RMergeList(head1, head2);

printf("递归合并：");

PrintList(head);

printf("\n");

}