单链表的实现

#include <iostream>
using namespace std;

struct listNode{
	int data;              //寄存本节点的数据 
	struct listNode* next; //寄存下一个节点的地位 
};
 
 
 
void insertNode(listNode *head, int pos, int value) {
	int step = 0;
	listNode* temp = new listNode;
	listNode* node = head;  //在后面转变了head的指向,须要先保留初始的head的指向 
	temp->data = value; 	//保留链表头的原始地位 
	while (step < pos) {	//感到这里须要记忆，比拟难懂得 
 		head = head->next;
		step++;
	} 
	temp->next = head->next;
	head->next = temp;
	head = node;	
}

void deleteNode(listNode *head, int pos) {
	listNode* node = head; //在后面转变了head的指向,须要先保留初始的head的指向 
	int step = 0;				
	while (step < pos) {
		head = head->next;
		step++;
	}
	listNode *previous = head->next; 
	head->next = head->next->next;	
	delete previous; 	//delete一个指针实际上是delete掉它指向的对象，delete掉head->next指向的对象 
	head = node;		
}

bool isEmpty(listNode *head) {
	return head->next == NULL? true : false; 
}

int size(listNode *head) {
	listNode* node = head;
	int count = 0;
	while (head->next != NULL) {
		count++;
		head = head->next;
	}
	head = node;
	return count;
}

//遍历全部链表 
void traverse(listNode* head) {
	listNode *node = head;
	head = head->next;
	while (head != NULL) {
		cout << head->data << endl;
		head = head->next;
	}
	head = node;
}

void clear(listNode* head) {
	listNode* temp;
	listNode* node = head;
	//这里要懂得一下 
	while(head->next != NULL) {
		temp = head->next->next;
		delete head->next;
		head->next = temp;
	}
	head = node;
}
#include <iostream>
using namespace std;

struct l