c语言单链表的增删改查、排序以及摧毁（代码） c

以下为本人对单链表的学习总结笔记，若有不对之处，望大家指出！！！
#include
#include
#include
#include
【c语言单链表的增删改查、排序以及摧毁（代码）】typedef int Type;
typedef struct List
{
Type num;

struct List *next;

}List_t;
List_t *Head = NULL;
int Head_Init()
{
Head = (List_t *)malloc(sizeof(List_t));
if(Head == NULL)
{
perror(“malloc fail\n”);
return -1;
}

Head->next = NULL; return 0;

}
void List_Add(Type n)
{
List_t *new = (List_t *)malloc(sizeof(List_t));
if(new == NULL)
{
perror(“malloc fail\n”);
return ;
}
new->num = n;

List_t *p = Head; while(p->next != NULL) { p = p->next; }p->next = new; new->next = NULL;

}
void List_Display()
{
int i = 0;
List_t *p = Head->next;

if(p == NULL) { printf("list is NULL\n"); return ; }printf("*******************\n"); while(p != NULL) { printf("[%d] : %d\n", i++, p->num); p = p->next; } printf("*******************\n");

}
void List_Change(Type old, Type new)
{
int flag = 0;

List_t *p = Head->next; while(p != NULL) { if(p->num == old) { p->num = new; flag = 1; } p = p->next; }if(flag == 1) { printf("change success\n"); } else { printf("change fail:the num does not exit\n"); }

}
void List_Delete(Type del_num)
{
int flag = 0;

List_t *pre = Head; List_t *q= pre->next; if(q == NULL) { printf("List is NULL"); return ; } else if(q->next == NULL) { if(q->num == del_num) { flag = 1; free(q); q = NULL; pre->next = NULL; } } else { while(q != NULL) { if(q->num == del_num) { flag = 1; List_t *tmp = q; q = q->next; pre->next = q; free(tmp); tmp = NULL; } else { pre = q; q = q->next; } } }if(flag == 1) { printf("delete success\n"); } else { printf("the num does not exit\n"); }

}
void List_Destroy()
{
List_t *q = Head->next;
List_t *tmp = NULL;
Head->next = NULL;

while(q != NULL) { tmp = q; q = q->next; free(tmp); tmp = NULL; } printf("\nDestroy success\n");

}
int List_Length()
{
int length = 0;

List_t *p = Head->next; while(p != NULL) { p = p->next; length++; } return length;

}
void List_Sort()
{
int i, j, length;
if(Head->next == NULL || Head->next->next == NULL)
{
return ;
}

List_t *pre = NULL; List_t *q = NULL; length = List_Length(); for(j=1; jnext; inum > q->next->num && q->next != NULL) { pre->next = q->next; q->next = pre->next->next; pre->next->next = q; } else { q = q->next; } pre = pre->next; } }

}
int main(void)
{
if(Head_Init() != 0)
{
printf(“head init fail\n”);
return -1;
}

int choice = 0; while(1) { printf("\n1.Add 2.Display 3.Exit 4.Change 5.Delete 6.Destroy 7.Sort\n"); scanf("%d", &choice); switch(choice) { case 1: { Type num = 0; printf("input : "); scanf("%d", &num); List_Add(num); break; } case 2: { List_Display(); break; } case 3: { printf("********exit**********\n"); return -1; } case 4: { Type old_num, new_num; printf("which num will be changed to which num\n"); scanf("%d %d", &old_num, &new_num); List_Change(old_num, new_num); break; } case 5: { Type delete_num; printf("Delete which num\n"); scanf("%d", &delete_num); List_Delete(delete_num); break; } case 6: { List_Destroy(); break; } case 7: { List_Sort(); break; } default: { printf("Do not have the chose, choice again,please\n"); break; } } } return -1;

}
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