/*
数据结构十六讲课后作业
独立思考了一个下午居然一遍就成功了,不可思议嘿嘿
明天再来查缺补漏,很值得回味呢
*/
#include "stdio.h"
#include "stdlib.h"
typedef void status;
typedef int ElemType;
//定义结点类型
typedef struct node{
int data;
struct node *next;
};
typedef struct node *Linklist;
//快慢指针确定链表中间数
status GetMidNode(Linklist L, ElemType *e){ //L为指向头结点的指针, e为指向存放中间数空间的指针
Linklist mid;
Linklist search;
search = L -> next;
mid = L -> next;
while(search -> next != NULL){
if (search ->next ->next != NULL){
search = search ->next -> next;
mid = mid -> next;
}
else{
search = search -> next;
}
}
*e = mid -> data;
return ;
}
//创建链表
status InitList(Linklist *L){ //指向(指针L)的指针
Linklist p, q;
q = *L;
for (int i = 0; i < 20; i++){
p = (Linklist) malloc(sizeof(struct node));
q -> next = p;
p -> data = rand()%100 + 1;
q = p;
}
p -> next = NULL;
return ;
}
//链表长度
int ListLength(Linklist L){ //L为指向头结点的指针
int j = 0;
while (L -> next != NULL){
L = L -> next;
j++;
}
return j;
}
//输出链表
status Getlist(Linklist L){ //L为指向头结点的指针
while (L -> next != NULL){
L = L -> next;
printf("%d ", L -> data);
}
return ;
}
int main(){
int i, j, e;
char ch;
Linklist L;
L = (Linklist) malloc(sizeof(struct node));
L -> next = NULL;
j = ListLength(L);
printf("初始化L后:ListLength(L) = %d\n\n", j);
printf("1.查看链表\n");
printf("2.创建随机链表\n");
printf("3.链表长度\n");
printf("4.中间结点值\n");
printf("0.退出\n");
printf("请选择你的操作:\n");
while ((ch = getchar()) != '0'){
if (ch == '1'){
Getlist(L);
printf("\n");
}
else if (ch == '2'){
InitList(&L);
Getlist(L);
printf("\n");
}
else if (ch == '3'){
j = ListLength(L);
printf("ListLength(L) = %d\n", j);
}
else if (ch == '4'){
GetMidNode(L, &e);
printf("%d\n", e);
}
}
return 0;
}