// FastSearch.cpp : 链表快速查找中间值,快慢指针的方法
#include "stdafx.h"
#include <stdlib.h>
struct LINKLIST
{
int data;
LINKLIST *next;
};
LINKLIST *head = (LINKLIST*)malloc(sizeof(LINKLIST));
//初始化链表(尾插法)
void ListInitial()
{
LINKLIST* p = new LINKLIST;
p = head;//找一个临时的节点,用于存放head指针的地址
for (size_t i = 1; i <= 20; i++)
{
LINKLIST* node = new LINKLIST;
node->data = i;
node->next = NULL;
p->next = node;
p = node;
}
}
LINKLIST* p2 = new LINKLIST;
//初始化链表(头插法)
void ListInitial_2()
{
p2->next = NULL;
for (size_t i = 0; i <= 20; i++)
{
LINKLIST* node = new LINKLIST;
node->data = i;
node->next = p2;
p2 = node;
}
}
//尾插法打印链表
bool printLinklist()
{
LINKLIST* p = new LINKLIST;
p = head;
int i = 0;
if (p->next==NULL)
{
return false;
}
while (p->next!=NULL)
{
i++;
p = p->next;
printf("a[%d]=%d\n",i, p->data);
}
return true;
}
//头插法打印链表
bool printLinklist_2()
{
int i = 0;
if (p2->next == NULL)
{
return false;
}
while (p2->next != NULL)
{
i++;
p2 = p2->next;
printf("a[%d]=%d\n", i, p2->data);
}
return true;
}
//快速查找中间值,快慢指针的方法
void midData()
{
LINKLIST *search=(LINKLIST*)malloc(sizeof(LINKLIST));
LINKLIST *data = (LINKLIST*)malloc(sizeof(LINKLIST));
search = head;
data = head;
int i = 0;
while (search->next!=NULL)
{
if (search->next->next!=NULL)
{
search = search->next->next;
data = data->next;
}
else
{
search = search->next;
data= data->next;
}
i++;
}
printf("中间值是a[%d]=%d\n",i, data->data);
}
int main()
{
ListInitial();
printLinklist();
midData();
return 0;
}
程序亲测有效,关于快慢指针的思想可以看https://www.bilibili.com/video/av29175690/?p=16这个视频