C++数据结构之链表的创建

// test_shared.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include <memory>#include <string>#include <iostream>typedef struct stage_tag {  int         data_ready;   /* Data present */  long        data;      /* Data to process */  struct stage_tag  *next;     /* Next stage */} stage_t;// 高效率的链表创建方式stage_t* TestLinkCreateClever(int stages){  stage_t *head = NULL,*new_stage = NULL,*tail = NULL;  stage_t **link = &head; // 区别在这个指针地址变量上,它起到绑定新的stage的作用.  for(int i =0; i<stages;++i)  {    new_stage = (stage_t*)malloc(sizeof(stage_t));       new_stage->data_ready = 0;    new_stage->data = i;    *link = new_stage; // 把新的stage赋值给link指向的指针地址    link = &new_stage->next; // 绑定下一个的指针地址  }  tail = new_stage;  *link = NULL;  return head;}// 低效率的链表创建方式stage_t* TestLinkCreateStupid(int stages){  stage_t *head = NULL,*new_stage = NULL,*tail = NULL;  for(int i =0; i<stages;++i)  {    new_stage = (stage_t*)malloc(sizeof(stage_t));       new_stage->data_ready = 0;    new_stage->data = i;    new_stage->next = NULL;    if(tail)      tail->next = new_stage;    else      head = new_stage;    tail = new_stage;  }  return head;}int _tmain(int argc, _TCHAR* argv[]){  std::cout << "=== TestLinkCreateClever ===" << std::endl;  auto first = TestLinkCreateClever(10);  while(first)  {    std::cout << "data: " << first->data << std::endl;    first = first->next;  }  std::cout << "=== TestLinkCreateStupid ===" << std::endl;  auto second = TestLinkCreateStupid(10);  while(second)  {    std::cout << "data: " << second->data << std::endl;    second = second->next;  }  return 0;}