求A-B(仅在A出现而不在B出现,并将结果保存在A):两个链表都是有序的,当p所指结点小于q所指结点的值,p后移一位。当q所指结点小于p所指结点的值,q后移一位。若两结点值相同,则删除p所指结点。
核心代码如下:
//求A与B的交叉集(仅在A中出现而不在B中出现),并将结果保存到链表A
void Difference(LNode *A,LNode *B)//时间复杂度O(m+n)
{
if(A == nullptr || B == nullptr)
return ;
LNode *p = A->next,*q = B->next;
LNode *r = A;//记录前置结点
while(p != nullptr && q != nullptr){
if(p->data < q->data)
{
r = p;
p = p->next;
}
else if(p->data > q->data)
{
q = q->next;
}
else
{
LNode *s = p;
r->next = p->next;//记得重新指向
p = p->next;
free(s);
}
}
}
void Difference_1(LNode *A,LNode *B)//时间复杂度O(m+n)
{
if(A == nullptr || B == nullptr)
return ;
LNode *p = A->next,*q = B->next;
LNode *r = A;//记录前置结点
r->next = nullptr;
while(p != nullptr && q != nullptr){
if(p->data < q->data)
{
r->next = p;
p = p->next;
r = r->next;
}
else if(p->data > q->data)
{
r->next = q;
q = q->next;
r = r->next;
}
else
{
LNode *s = p;
LNode *s2 = q;
p = p->next;
q = q->next;
free(s);
free(s2);
}
}
r->next = nullptr;
}
程序完整代码如下:
#include<stdio.h>
#include<malloc.h>
using namespace std;
typedef struct LNode{
int data;
struct LNode *next;
}LNode;
void CreatelistR(LNode *&head,int arr[],int n);//尾插法创建带头结点的单向链表
void ShowList(LNode *head);
//求A与B的交叉集(仅在A中出现而不在B中出现),并将结果保存到链表A
void Difference(LNode *A,LNode *B);//时间复杂度O(m+n)
//去掉A与B重复的部分,并将剩余数字全部保存到链表A
void Difference_1(LNode *A,LNode *B);
int main(){
puts("链表1:");
LNode *head = nullptr;
int arr[] = {7,9,12,16,18,23,26,28,35,70};
CreatelistR(head,arr,sizeof(arr)/sizeof(arr[0]));
ShowList(head);
puts("链表2:");
LNode *head_2 = nullptr;
int arr_2[] = {12,14,23,26,29,35,37,39,46,70};
CreatelistR(head_2,arr_2,sizeof(arr_2)/sizeof(arr_2[0]));
ShowList(head_2);
puts("A-B:");
Difference(head,head_2);
ShowList(head);
CreatelistR(head,arr,sizeof(arr)/sizeof(arr[0]));
CreatelistR(head_2,arr_2,sizeof(arr_2)/sizeof(arr_2[0]));
puts("去掉A与B重复的部分,并将剩余数字全部保存到链表A:");
Difference_1(head,head_2);
ShowList(head);
return 0;
}
void CreatelistR(LNode *&head,int arr[],int n)//尾插法
{
if(arr == nullptr || n < 0)
return;
head = (LNode *)malloc(sizeof(LNode));
head->next = nullptr;
LNode *temp = head;
for(int i=0;i<n;i++)
{
LNode *node = (LNode *)malloc(sizeof(LNode));
node->data = arr[i];
node->next = nullptr;
temp->next = node;
temp = temp->next;
}
}
void ShowList(LNode *head){
if(head == nullptr)
return;
while(head->next != nullptr)
{
printf("%d ",head->next->data);
head = head->next;
}
puts("");
puts("");
}
//求A与B的交叉集(仅在A中出现而不在B中出现),并将结果保存到链表A
void Difference(LNode *A,LNode *B)//时间复杂度O(m+n)
{
if(A == nullptr || B == nullptr)
return ;
LNode *p = A->next,*q = B->next;
LNode *r = A;//记录前置结点
while(p != nullptr && q != nullptr){
if(p->data < q->data)
{
r = p;
p = p->next;
}
else if(p->data > q->data)
{
q = q->next;
}
else
{
LNode *s = p;
r->next = p->next;//记得重新指向
p = p->next;
free(s);
}
}
}
void Difference_1(LNode *A,LNode *B)//时间复杂度O(m+n)
{
if(A == nullptr || B == nullptr)
return ;
LNode *p = A->next,*q = B->next;
LNode *r = A;//记录前置结点
r->next = nullptr;
while(p != nullptr && q != nullptr){
if(p->data < q->data)
{
r->next = p;
p = p->next;
r = r->next;
}
else if(p->data > q->data)
{
r->next = q;
q = q->next;
r = r->next;
}
else
{
LNode *s = p;
LNode *s2 = q;
p = p->next;
q = q->next;
free(s);
free(s2);
}
}
r->next = nullptr;
}
运行结果如下: