链表操作

#define _CRT_SECURE_NO_DEPRECATE  /*取消scanf,printf不安全之类的错误提示*/
#include <stdio.h>
#include <stdlib.h>

typedef struct node
{
	int value;
	struct node* next;
}listnode;

listnode* Creat_List1(int nodenum, int *data); //最先进去的元素在最后面
listnode* Creat_List2(int nodenum, int *data); //最先进去的元素在最前面
int Get_Link_Element(listnode* head, int i); //取得头指针为head的链表中的第i个元素的值(包括第0个元素)
void Insert_List(listnode* head, int a, int i);
void Delet_List(listnode* head, int i); //删除第i个元素
listnode* Merge_TWO_Linklist(listnode *list1, listnode *list2);//合并两个有序链表

int main()
{
	int data;
	listnode *linka, *linkb, *linkc, *linkd, *linke;
	linka = (listnode*)malloc(sizeof(listnode));
	linkb = (listnode*)malloc(sizeof(listnode));
	linkc = (listnode*)malloc(sizeof(listnode));
	linkd = (listnode*)malloc(sizeof(listnode));
	linke = (listnode*)malloc(sizeof(listnode));
	int a[5] = { 1, 3, 5, 7, 9 };
	int b[3] = { 2,2, 4 };
	linka = Creat_List2(5, a);
	linkb = Creat_List2(3, b);
	Insert_List(linkb, 10, 1);
	Delet_List(linkb, 1);
	linkc=Merge_TWO_Linklist(linka, linkb);
	data = Get_Link_Element(linkb, 1);
	printf("%d\n", data);
}

//新元素总是插入到头指针后面，结果就是原先的元素一直往后移
listnode* Creat_List1(int nodenum,int *data)
{
	listnode *pc; //保存新节点
	listnode *head;
	head = (listnode*)malloc(sizeof(listnode));
	head->next = NULL; //先建立一个带头结点的单链表
	/*开始插入元素*/
	for (int i = 0; i < nodenum; i++)
	{
		pc = (listnode*)malloc(sizeof(listnode));
		pc->value = data[i];
		pc->next = head->next;
		head->next = pc;
	}
	return head;
}
//新元素插入到头指针前面，头指针一直往后移
listnode* Creat_List2(int nodenum, int *data)
{
	listnode *pc; //保存新节点
	listnode *head;
	listnode *r;//保存产生的链表
	head = (listnode*)malloc(sizeof(listnode));
	head->next = NULL; //先建立一个带头结点的单链表
	r = head;
	/*开始插入元素*/
	for (int i = 0; i < nodenum; i++)
	{
		pc = (listnode*)malloc(sizeof(listnode));
		pc->value = data[i];
		head->next = pc;
		pc->next = NULL;
		head = pc;
	}
	return r;
}

//取得头指针为head的链表中的第i个元素的值(包括第0个元素)
int Get_Link_Element(listnode* head, int i)
{
	/*创建一个扫描指针，让它指向第一个元素*/
	listnode* pc;
	int j = 0; //计数
	pc = (listnode*)malloc(sizeof(listnode));
	pc = head->next;
	while (pc != NULL && j < i) //遍历
	{
		pc = pc->next;
		j++;
	}
	if (pc == NULL || j > i) exit(-1);
	return pc->value;
}

/*
*合并两个有序链表,把list2合并到list1
*/
listnode* Merge_TWO_Linklist(listnode *list1, listnode *list2)
{
	listnode *pc1, *pc2, *pc3,*list3;
	pc1 = (listnode*)malloc(sizeof(listnode));
	pc2 = (listnode*)malloc(sizeof(listnode));
	pc3 = (listnode*)malloc(sizeof(listnode));


	pc1 = list1->next;
	pc2 = list2->next;
	pc3 = list1;
	list3 = pc3;
	while (pc1 != NULL && pc2 != NULL)
	{
		if (pc1->value <= pc2->value) {
			pc3->next = pc1;
			pc3 = pc3->next;
			pc1 = pc1->next;
		}
		else{
			pc3->next = pc2;
			pc3 = pc3->next;
			pc2 = pc2->next;
		}
	}
	if (pc1 == NULL) pc3->next = pc2;
	if (pc2 == NULL) pc3->next = pc1;
	free(list2);
	return list3;
}

void Insert_List(listnode* head, int a, int i)
{
	listnode *pc;
	listnode *s;
	pc = head->next;//令pc指向第一个元素
	int j = 1;
	while (pc != NULL && j < i)
	{
		pc = pc->next; //pc后移动
		j++;
	}
	if (pc == NULL)
	{
		printf("error\n");
		exit(-1);
	}

	s = (listnode*)malloc(sizeof(listnode));
	s->value = a;
	s->next = pc->next;
	pc->next = s;
}

//删除第i个元素
void Delet_List(listnode* head, int i)
{
	listnode *temp = NULL;
	int j = 1; //计数
	head = head->next;
	while (head != NULL && j < i)
	{
		head = head->next;
		j++;
	}
	if (head == NULL)
	{
		printf("error\n");
		exit(-1);
	}
	temp = head->next;
	head->next = temp->next;
	//head = head->next->next;
	free(temp);
}

　　

#define _CRT_SECURE_NO_DEPRECATE

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <stack>
#include <stdio.h>
#include <stdlib.h>
using namespace std;

struct ListNode
{
    int value;
    ListNode *next;
};
//创建一个只含头结点的链表
ListNode* CreatListHead()
{
    ListNode* pHead = (ListNode*)malloc(sizeof(ListNode));
    pHead->next = NULL;

    return pHead;
}

//插入节点到末尾
void AddToTail(ListNode** pHead, int Value)
{
    //申请空间,构造新插入的节点
    ListNode *pNew = (ListNode*)malloc(sizeof(ListNode));
    pNew->value = Value;
    pNew->next = NULL;
    //如果原来的链表为空,则插入的节点作为头结点
    if(*pHead == NULL)
    {
        *pHead = pNew;
    }
    else
    {
        //找到最后一个节点
        ListNode *pNode = *pHead; //声明一个指针指向当前的头结点
        while(pNode->next != NULL)
        {
            pNode = pNode->next; //节点后移，直到最后一个节点
        }
        //插入新节点
        pNode->next = pNew;
    }
}

void RemoveNode(ListNode** pHead, int value)
{
    if(pHead == NULL || *pHead == NULL)
        return;
    ListNode* ToBeDeleted = NULL;
    //如果要删除的节点在链表头
    if((*pHead)->value == value)
    {
        ToBeDeleted = *pHead;
        *pHead = (*pHead)->next;
    }
    else
    {
        //声明一个指针指向头节点
        ListNode* pNode = *pHead;
        //遍历链表,知道找到要删除的节点
        while(pNode->next != NULL && pNode->next->value != value)
            pNode = pNode->next;
        if(pNode->next != NULL && pNode->next->value == value)
        {
            ToBeDeleted = pNode->next;
            pNode->next = pNode->next->next; //删除节点
        }
        if(ToBeDeleted != NULL)
        {
            free(ToBeDeleted);
            ToBeDeleted = NULL;
        }
    }
}

//递归方式从尾到头打印链表
void PrintListReversingly(ListNode *pHead)
{
    if(pHead != NULL)
    {
        if(pHead->next != NULL)
            PrintListReversingly(pHead->next);
    }
    printf("%d\t", pHead->value);
}

//栈方式从尾到头打印链表
void PrintListResversingly_Stack(ListNode *pHead)
{
    std::stack<ListNode*> nodes;

    ListNode* pNode = pHead;
    while(pNode != NULL)
    {
        nodes.push(pNode);
        pNode = pNode->next;
    }
    while(!nodes.empty())
    {
        pNode = nodes.top();
        printf("%d\t", pNode->value);
        nodes.pop();
    }
}

int main()
{
    int a[] = {1,2,3,4,5};
    int size = sizeof(a) / sizeof(int);
    ListNode* pList = CreatListHead(); //包含空头结点的链表
    ListNode* pList2 = NULL;

    AddToTail(&pList, 5);
    for(int i = 0; i < size; i++)
    {
        AddToTail(&pList2, a[i]);
    }
    RemoveNode(&pList2, 4);
    PrintListReversingly(pList2);
    PrintListResversingly_Stack(pList2);
}