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2022-8-10
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note
一.温故知新
栈式的存储结构
先进后出
队列式的存储结构
先进先出
无论是顺序表还是链表都可以实现
栈式
struct node
{
int stack[6];
int ind;
};
队列
struct node
{
int queue[6];
int front;
int rear;
};
静态库和动态库
早测
1.链表中倒数第k个结点
给定一个头结点为handler的单向不循环链表
输出该链表中倒数第k个结点
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| struct llist_node *func(struct llist_node *l, int k)
{
struct llist_node *s = l;
struct llist_node *f = l;
while(k--)
{
if(f == NULL)
return NULL;
f = f->next;
}
while(f != NULL)
{
s = s->next;
f = f->next;
}
}
|
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| struct llist_node *func(struct llist_node *l1, struct llist_node *l2)
{
struct llist_node *l = NULL;
struct llist_node *cur = NULL;
if(l1 == NULL)
return l2;
if(l2 == NULL)
return l1;
if(l1->val < l2->val)
{
l = cur = l1;
l1 = l1->next;
}
else
{
l = cur = l2;
l2 = l2->next;
}
while(l1 != NULL && l2 != NULL)
{
if(l1->val < l2->val)
{
cur->next = l1;
l1 = l1->next;
}
else
{
cur->next = l2;
l2 = l2->next;
}
cur = cur->next;
}
if(l1 != NULL)
cur->next = l1;
if(l2 != NULL)
cur->next = l2;
return l;
}
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内核链表
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| /usr/src/linux-hwe-5.4-headers-5.4.0-122/include/linux
list.h
struct list_head
{
struct list_head *prev;
struct list_head *next;
};
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)
LIST_HEAD(handler);
|
test.c
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| #include <stdio.h>
#include <stdlib.h>
struct list_head
{
struct list_head *prev;
struct list_head *next;
};
struct stu
{
int id;
char name[20];
int math;
struct list_head node;
};
int main(int argc, char *argv[])
{
struct stu s;
printf("&s = %p\n", &s);
printf("&s.id = %p\n", &s.id);
printf("s.name = %p\n", s.name);
printf("&s.math = %p\n", &s.math);
printf("&s.node = %p\n", &s.node);
printf("SIZE=%ld\n", (size_t)&(((struct stu *)0)->node));
return 0;
}
|
kernellist
list.h
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| #ifndef _MYTEST_LIST_H
#define _MYTEST_LIST_H
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#define container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
(type *)( (char *)__mptr - offsetof(type,member) );})
struct list_head {
struct list_head *prev;
struct list_head *next;
};
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)
static inline void INIT_LIST_HEAD(struct list_head *list)
{
list->next = list;
list->prev = list;
}
static inline void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
{
next->prev = new;
new->next = next;
new->prev = prev;
prev->next = new;
}
static inline void list_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
__list_add(new, head->prev, head);
}
static inline void __list_del(struct list_head * prev, struct list_head * next)
{
next->prev = prev;
prev->next = next;
}
static inline void list_del(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
entry->next = NULL;
entry->prev = NULL;
}
#define list_entry(ptr, type, member) \
container_of(ptr, type, member)
#define list_for_each(pos, head) \
for (pos = (head)->next; pos != (head); pos = pos->next)
#endif
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kernellist.c
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|
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "list.h"
#define NAMESIZE 20
typedef struct stu
{
int id;
char name[NAMESIZE];
int math;
struct list_head node;
}STU;
void print(const void *data)
{
const STU *p = data;
printf("%d %s %d\n", p->id, p->name, p->math);
}
int id_cmp(const void *data, const void *key)
{
const STU *p = data;
const int *k = key;
return !(p->id - *k);
}
int name_cmp(const void *data, const void *key)
{
const STU *p = data;
const char *k = key;
return !(strcmp(p->name, k));
}
int main(void)
{
LIST_HEAD(handler);
STU *data = NULL;
STU *datap = NULL;
struct list_head *pos = NULL;
int i = 0;
int find_id = 100;
char *find_name = "stu4";
for(i = 0; i < 5; i++)
{
data = malloc(sizeof(STU));
if(data == NULL)
continue;
data->id = 100 + i;
sprintf(data->name, "stu%d", i);
data->math = 100 - i;
list_add_tail(&data->node, &handler);
}
list_for_each(pos, &handler)
{
datap = list_entry(pos, STU, node);
print(datap);
}
printf("----------------------\n");
list_for_each(pos, &handler)
{
datap = list_entry(pos, STU, node);
if(name_cmp(datap, "stu9"))
{
printf("Find It!\n");
print(datap);
}
}
printf("----------------------\n");
list_for_each(pos, &handler)
{
datap = list_entry(pos, STU, node);
list_del(pos);
free(datap);
pos = &handler;
}
return 0;
}
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