//参考书是机械工业出版社的数据结构与算法分析(C语言描述);
//本程序是可移植性程序;
//能在Linux/Mac os/Windows下编译运行;
//若有不足之处请提出，博主会尽所能修改;
//若是对您有用的话请点赞收藏或分享给它人;
//未经允许严禁抄袭以及转载;
//源代码奉上,希望能够对您有所启发;
//----------------------------------------------------------------------------
//main.c
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include "linkedlist.h"
int show_menu(void); //显示主菜单;
int get_first(void); //获取用户输入的第1个字符;
void eatline(void); //清空输入缓冲区;
elemtype input(void); //获取用户输入的数据元素;
void choice(int ch, linkedlist head); //操作链表中的数据元素;
int main(void)
{
int ch;
linkedlist list = init_list_head();
while ((ch = show_menu()) != 'q')
{
choice(ch, list);
}
destroy_list(list);
printf("本程序完成!\n");
return 0;
}
int show_menu(void)
{
int ch;
puts("========================================");
puts("a) 判断链表是否为空");
puts("b) 查看链表数据元素个数");
puts("c) 查找链表某数据是否存在");
puts("d) 在头结点后插入新的数据元素");
puts("e) 删除某个数据元素");
puts("f) 遍历链表");
puts("q) 退出本程序");
puts("========================================");
printf("请您输入选择:");
ch = get_first();
while (strchr("abcdefq", ch) == NULL)
{
printf("您的输入无效!请重新输入:");
ch = get_first();
}
return ch;
}
int get_first(void)
{
int ch;
do
{
ch = tolower(getchar());
} while (isspace(ch));
eatline();
return ch;
}
void eatline(void)
{
while (getchar() != '\n')
continue;
return;
}
elemtype input(void)
{
elemtype temp;
printf("请您输入一个数据元素:");
while (scanf("%d", &temp) != 1)
{
eatline();
printf("数据无效!请重新输入:");
}
eatline();
return temp;
}
void choice(int ch, linkedlist head)
{
pnode *pos;
elemtype val;
switch (ch)
{
case 'a':
{
printf("链表%s!\n", list_is_empty(head) ? "为空" : "非空");
break;
}
case 'b':
{
printf("链表中元素个数: %d个\n", list_length(head));
break;
}
case 'c':
{
val = input();
if (find(val, head))
{
printf("链表中存在元素%d\n", val);
}
else
{
printf("链表中不存在元素%d\n", val);
}
break;
}
case 'd':
{
val = input();
insert(head, head, val);
printf("在头结点后插入数据元素%d成功!\n", val);
break;
}
case 'e':
{
val = input();
if (cancel(head, val))
{
printf("删除数据元素%d成功!\n", val);
}
else
{
printf("链表中不存在元素%d, 删除失败\n", val);
}
break;
}
case 'f':
{
if (!list_is_empty(head))
{
printf("链表中数据元素如下:\n");
traverse(head);
}
else
{
printf("链表为空无法遍历!\n");
}
break;
}
}
printf("\n\n\n\n\n\n\n\n\n\n\n\n");
return;
}
//linkedlist.h
#ifndef LINKEDLIST_H_
#define LINKEDLIST_H_
#include <stdbool.h>
typedef int elemtype; //本程序使用的数据元素是最简单的整型元素, 可随使用情况修改;
typedef struct node
{
elemtype data;
struct node *next;
} * linkedlist;
typedef struct node pnode;
//1) 构造一个链表头结点;
linkedlist init_list_head(void);
/*----------------------------------------------------------------------*/
//2) 销毁链表;
void destroy_list(linkedlist head);
/*----------------------------------------------------------------------*/
//3) 判断结点是否为尾结点;
bool node_is_last(linkedlist pos);
/*----------------------------------------------------------------------*/
//4) 判断链表是否为空;
bool list_is_empty(linkedlist head);
/*----------------------------------------------------------------------*/
//5) 获取链表数据元素个数;
int list_length(linkedlist head);
/*----------------------------------------------------------------------*/
//6) 查找链表中指定值的位置;
pnode *find(elemtype x, linkedlist head);
/*----------------------------------------------------------------------*/
//7) 查找链表中指定值的前驱结点位置;
pnode *find_previous(elemtype x, linkedlist head);
/*----------------------------------------------------------------------*/
//8) 在链表第pos个位置后插入新数据x;
void insert(linkedlist head, pnode *pos, elemtype x);
/*----------------------------------------------------------------------*/
//9) 删除链表中的数据元素x;
bool cancel(linkedlist head, elemtype x);
/*----------------------------------------------------------------------*/
//10) 遍历链表;
void traverse(linkedlist head);
/*----------------------------------------------------------------------*/
#endif
//linkedlist.c
#include <stdio.h>
#include <stdlib.h>
#include "linkedlist.h"
linkedlist init_list_head(void)
{
pnode *head = (pnode *)malloc(sizeof(pnode));
if (NULL == head)
{
fprintf(stderr, "动态内存分配失败!本程序退出!\n");
exit(EXIT_FAILURE);
}
head->next = NULL;
return head;
}
void destroy_list(linkedlist head)
{
pnode *temp = NULL;
while (head != NULL)
{
temp = head;
head = head->next;
free(temp);
}
return;
}
bool node_is_last(linkedlist pos)
{
return NULL == pos->next;
}
bool list_is_empty(linkedlist head)
{
return NULL == head->next;
}
int list_length(linkedlist head)
{
int len = 0;
pnode *pos = head->next;
while (pos != NULL)
{
++len;
pos = pos->next;
}
return len;
}
pnode *find(elemtype x, linkedlist head)
{
pnode *pos = head->next;
while (pos != NULL && pos->data != x)
{
pos = pos->next;
}
return pos;
}
pnode *find_previous(elemtype x, linkedlist head)
{
pnode *pos = head;
while (pos->next != NULL && pos->next->data != x)
{
pos = pos->next;
}
return pos;
}
void insert(linkedlist head, pnode *pos, elemtype x)
{
pnode *new_node = (pnode *)malloc(sizeof(pnode));
if (NULL == new_node)
{
fprintf(stderr, "动态内存分配失败!本程序退出!\n");
exit(EXIT_FAILURE);
}
new_node->data = x;
new_node->next = pos->next;
pos->next = new_node;
return;
}
bool cancel(linkedlist head, elemtype x)
{
pnode *temp;
pnode *pos = find_previous(x, head);
if (!node_is_last(pos))
{
temp = pos->next;
pos->next = temp->next;
free(temp);
return true;
}
return false;
}
void traverse(linkedlist head)
{
pnode *pos = head->next;
while (pos != NULL)
{
printf("%d ", pos->data);
pos = pos->next;
}
return;
}
//----------------------------------------------------------------------------
//----------------------------2021年1月12日 -------------------------------