#include <stdio.h>
#include <stdlib.h>
typedef struct myString {
char ch;
struct myString *next;
}LinkedList;
void Traverse(LinkedList* list) {
if (list != NULL) {
list = list->next; //头结点没存数据
}
while (list != NULL) {
printf("\nTraversing,current ch is: %c\n", list->ch);
list = list->next;
}
}
LinkedList* create(int n) {
if (n >= 0) {
LinkedList *head, *node, *rear;
head = (LinkedList*)malloc(sizeof(LinkedList));
rear = head;
for (int i = 0; i < n; i++) {
node = (LinkedList*)malloc(sizeof(LinkedList));
puts("请输入一个字符:");
scanf(" %c", &node->ch);
rear->next = node;
rear = node;
}
rear->next = NULL;
puts("链表创建成功\n");
return head;
}
else {
puts("创建失败！\n");
}
}
void change(LinkedList *list, int n) { //n代表位置
if (n >= 0) {
LinkedList *t = list;
int i = 0;
while (i < n && t != NULL) {
t = t->next;
i++;
}
if (t != NULL) {
puts("请输入一个字符\n");
scanf(" %c", &t->ch);
}
else {
printf("%d号节点不存在！\n", n);
}
}
else {
printf("%d号节点不存在！\n", n);
}
}
void delete(LinkedList *list, int n) {
if (n >= 0) {
LinkedList* p = list;
int i = 0;
while (p != NULL && i < n) {
p = p->next;
i++;
}
if (p == NULL) {
printf("%d号待删除节点不存在！\n", n);
}
else if (n != 0) {
//这里O(n)，如果用双向链表就会好很多
//其实也可不用 参见法2
LinkedList* q = list;
{
while (q->next != p) { q = q->next; }
q->next = p->next;
free(p);
printf("remove OK!Now traverse\n");
Traverse(list);
/* list = list->next;
while (list->next != NULL) {
printf("%c\n", list->ch);
list = list->next;
}
printf("%c\n", list->ch);*/
}
}
else {
printf("待删除节点不存在！\n");
}
}
else {
printf("待删除节点不存在！\n");
}
}
void delete2(LinkedList* list, int n) {
if (n >= 0) {
//这个方法更巧妙，不用重头开始遍历
LinkedList *p = list, *q = NULL;
int i = 0;
while (i < n && p != NULL) {
q = p;
p = p->next;
i++;
}
if (p != NULL && q != NULL) {
q->next = p->next;
free(p);
puts("法2删除成功！\n");
printf("remove OK!Now traverse\n");
Traverse(list);
}
else {
puts("法2删除失败！不存在该节点！\n");
}
}
else {
puts("法2删除失败！不存在该节点！\n");
}
}
void insertPrev(LinkedList* list, int n) {
if (n >= 0 && ((int)n == n)) {
LinkedList* p = list, *q = NULL;
int i = 0;
while (i < n && p != NULL) {
q = p;
p = p->next;
i++;
}
if (p != NULL && q != NULL) {
LinkedList* new = (LinkedList*)malloc(sizeof(LinkedList));
puts("请输入插入的一个字符:\n");
scanf(" %c", &new->ch);
q->next = new;
new->next = p;
printf("前插入%c成功！", new->ch);
}/*
else if (q == NULL) {
LinkedList* new = (LinkedList*)malloc(sizeof(LinkedList));
puts("请输入插入的一个字符:\n");
scanf_s(" %c", &new->ch);
new->next = p;
*pp = new;
}*/
else {
printf("待插入位置不存在！请重新输入！\n");
}
}
else {
printf("待插入位置不存在！请重新输入！\n");
}
}
void insertNext(LinkedList* list, int n) {
if (n >= 0) {
LinkedList *p = list, *q;
int i = 0;
while (i < n && p != NULL) {
p = p->next;
i++;
}
if (p != NULL) {
q = (LinkedList*)malloc(sizeof(LinkedList));
puts("请输出要插入的值：\n");
scanf(" %c", &q->ch);
q->next = p->next;
p->next = q;
printf("后插%c成功！\n", q->ch);
}
else {
printf("节点不存在！请重新插入!\n");
}
}
else {
printf("节点不存在！请重新插入!\n");
}
}
int main(int argc, char* argv[]) {
LinkedList* p = (LinkedList*)malloc(sizeof(LinkedList));
//LinkedList **pp = &p;
printf("--------------------Welcome to LinkedList World---------------------\n");
//printf("Now u can choose below selections.\n");
char* select[7] = { "0 create\n","1 insertPrev\n","2 insertNext\n","3 change\n","4 delete\n","5 delete2\n","6 traverse\n" };
/*
for(int i=0;i<7;i++){
printf("%s\n",select[i]);
}
*/
LinkedList* list = NULL;
while (1) {
fflush(stdin);
int n;
printf("\nNow u can choose below selections.\n");
for (int i = 0; i < 7; i++) {
printf("%s\n", select[i]);
}
scanf(" %d", &n);
if ((int)n == n) {
switch (n) {
case 0: {
int nums;
puts("Input numbers of nodes.\n");
scanf(" %d", &nums);
list = create(nums);
break;
}
case 1: {
puts("Input PrevInsertion position please.\n");
int pos;
scanf(" %d", &pos);
insertPrev(list, pos);
break;
}
case 2: {
puts("Input NextInsertion position please.\n");
int pos;
scanf(" %d", &pos);
insertNext(list, pos);
break;
}
case 3: {
puts("Input index for your change position.\n");
int pos;
scanf(" %d", &pos);
change(list, pos);
break;
}
case 4: {
puts("Input index for your delete position.\n");
int pos;
scanf(" %d", &pos);
delete(list, pos);
break;
}
case 5: {
puts("Input index for your delete2 position.\n");
int pos;
scanf(" %d", &pos);
delete2(list, pos);
break;
}
case 6: {
Traverse(list);
break;
}
default: {
break; //只能跳出switch 跳不出while(1)
}
}
}
}
}