自己编的C语言单链表的实现

头文件sll_node.h

#include<stdio.h>
#include<stdlib.h>

struct NODE
{
int value;
struct NODE *next;
};
typedef struct NODE Node;

//这里的root是在link_main文件中的定义的,同时应用于input.cpp文件，

//该文件中没有定义指针root，
//其结果是在调用过input函数之后，root值改变，不再为NULL；

extern Node *root;

bool sell_insert(Node **,int );  //插入节点函数

void show(Node *);    //显示链表数据函数

void input_data(Node **);  //输入链表数据函数

void free_list(Node **);  //释放链表内存函数

unsigned int count(Node *);     //链表节点计数函数

bool check(Node *,int);   //检查输入的数据是否在聊表中已经存在的函数

//链表排序函数——冒泡法,不改变节点位置，只改变节点中数据的存储位置

void sort(Node *);

void delete_data(Node **,int); //删除节点函数

子函数文件node.c

#include "sll_node.h"

//遍历链表——检查输入的数据是否与链表中的数据重复
bool
check(Node *root,int value)

{
Node *current;
current = root;
while(current != NULL)
{
if(current->value != value)
current = current->next;
else
break;
}

if(current == NULL)
return true;       //输入的数据没有与链表中的数据重复，返回true
else
return false;
}

//删除节点函数

void
delete_data(Node **phead,int delete_value)
{
Node *current;
Node *previous;
Node *next;
Node *pt;

current = *phead;
previous = NULL;

while(current->value != delete_value)
{
previous = current;
current = current->next;
next = current->next;
}

if(previous == NULL)
*phead = current->next;
else
previous->next = next;
pt = current;
free(pt);
}

//输入函数
void
input_data(Node **phead)
{
int value;
Node *current,*prev;
root = *phead;
puts("Enter the first value(q to end):");
while(scanf("%d",&value)==1)
{
while(getchar() != '\n')
continue;

current = (Node *)malloc(sizeof(Node));
if(root == NULL)
root = current;
else
prev->next = current;
current->next = NULL;
current->value = value;
puts("Enter the next value(q to end):");
prev = current;
}
}

//插入节点函数
bool
sell_insert(Node **phead,int new_value)
{
Node *current;
Node *previous;
Node *newn;

current = *phead;
previous = NULL;

while(current != NULL && current->value < new_value)
{
previous = current;
current = current->next;
}

newn = (Node *)malloc(sizeof(Node));
if(newn == NULL)
return false;

newn->value = new_value;
newn->next = current;
if(previous==NULL)
*phead = newn;
else
previous->next = newn;

return true;
}

//节点计数函数
unsigned int
count(Node *root)
{
unsigned int count = 0;
while(root != NULL)
{
++count;
root = root->next;
}

return count;
}

//显示函数
void
show(Node *root)
{
Node *current;
if(root == NULL)
printf("No data entered.");

current = root;
while(current != NULL)
{
printf(" %d ",current->value);
current = current->next;
}
}

//冒泡法排序链表函数——不改变节点位置，只改变节点中数据的存储位置void
sort(Node *root)
{
Node *current;
Node *s;

for(current = root;current->next != NULL;current = current->next)
{
for(s = root;s->next != NULL;s = s->next)
{
if(s->value > s->next->value)
{
int temp;
temp = s->value;
s->value = s->next->value;
s->next->value = temp;
}
}
}

}

//释放节点内存函数
void
free_list(Node **phead)
{
Node *psave;
while(*phead != NULL)
{
psave = (*phead)->next;
free(*phead);
*phead = psave;
}
}

主函数实现文件link_main.c

#include "sll_node.h"

Node *root = NULL;

int main()
{

//输入数据，分配内存，并输入原始序列和排序后的序列
input_data(&root);
if(root== NULL)
printf("No data entered.");
else
{
printf("Here is the list:\n");
show(root);
printf("\nThe sorted list is:\n");
sort(root);
show(root);
printf("\nTotal itms of the list is:\n %d",count(root));
}

//输入需要添加的数据
while(getchar() != '\n')
continue;

//这两句不可少，防止scanf因最后一次读取到的是字母而永远不会越过它
int new_value;
printf("\nNow enter the new value:\n");
scanf("%d",&new_value);
while(getchar() != '\n')
continue;

//检查待添加的数据是否在链表中存在，若存在，提示重新输入，直到不存在为止
while(!check(root,new_value) )
{
printf("Existed in the list ,please input another data:");
scanf("%d",&new_value);
while(getchar() != '\n')
continue;
}

//将待添加的数据加入新建的节点，并分配内存，插入链表，显示插入后的序列
if(sell_insert(&root,new_value))
{
printf("\nNow the list is:\n");
show(root);
printf("\nNow total itms of the list is:\n %d",count(root));
}
else
printf("insert error\n");
printf("\n");

//输入待删除的数据
int delete_value;
printf("\nNow enter the deleted value:\n");
scanf("%d",&delete_value);
while(getchar() != '\n')
continue;

//如果待删除的数据不在链表中，提示重新输入，知道存在为止
while(check(root,delete_value) )
{
printf("Not exist in the list ,please input a data in the list:");
scanf("%d",&delete_value);
while(getchar() != '\n')
continue;
}

//将待删除的数据所在的节点所占用的内存释放掉，即删除掉，重新链接链表，并显示删除数据后的序列

delete_data(&root,delete_value);
printf("\nNow the list is:\n");
show(root);
printf("\nNow total itms of the list is:\n %d",count(root));
printf("\n");

//释放链表所占用的内存

free_list(&root);

return 0;
}