链表

链表也是一种数据结构，它就是用来对链式
物理结构进行管理的
链表可以把链式物理结构的管理代码和其他
代码分隔开

链表的功能主要包含插入，删除，查找和遍历

/*
    链表演示
*/
#ifndef    __04LINK_H__
#define    __04LINK_H__
typedef struct node {
    int num;
    struct node *p_next;
} node;
typedef struct {
    node head, tail;
} link;
//初始化函数
void link_init(link *);
//清理函数
void link_deinit(link *);
//获得有效数字个数的函数
int link_size(const link *);
//在链表头加入数字
void link_add_head(link *, int );
//在链表末尾追加数字
void link_append(link *, int );
//按顺序加入数字的函数
void link_insert_in_order(link *, int );
//删除最前边数字的函数
void link_remove_head(link *);
//删除最后一个结点的函数
void link_remove_tail(link *);
//获得最前面数字的函数
int link_get_head(const link *, int *);
//获得最后一个数字的函数
int link_get_tail(link *, int *);
#endif   //__04LINK_H__





/*
    链表演示
*/
#include <stdlib.h>
#include "04link.h"
//初始化函数
void link_init(link *p_link) {
    p_link->head.p_next = &(p_link->tail);
    p_link->tail.p_next = NULL;
}
//清理函数
void link_deinit(link *p_link) {
    while (p_link->head.p_next != &(p_link->tail)) {
        node *p_first = &(p_link->head);
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        p_first->p_next = p_last;
        free(p_mid);
        p_mid = NULL;
    }
}
//获得有效数字个数的函数
int link_size(const link *p_link) {
    int cnt = 0;
    const node *p_node = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        const node *p_first = p_node;
        const node *p_mid = p_first->p_next;
        const node *p_last = p_mid->p_next;
        if (p_mid != &(p_link->tail)) {
            cnt++;
        }
    }
    return cnt;
}
//在链表头加入数字
void link_add_head(link *p_link, int num) {
    node *p_first = NULL, *p_mid = NULL, *p_last = NULL;
    node *p_tmp = (node *)malloc(sizeof(node));
    if (!p_tmp) {
        return ;
    }
    p_tmp->num = num;
    p_tmp->p_next = NULL;
    p_first = &(p_link->head);
    p_mid = p_first->p_next;
    p_last = p_mid->p_next;
    p_first->p_next = p_tmp;
    p_tmp->p_next = p_mid;
}
//在链表末尾追加数字
void link_append(link *p_link, int num) {
    node *p_tmp = (node *)malloc(sizeof(node));
    node *p_node = NULL;
    if (!p_tmp) {
        return ;
    }
    p_tmp->num = num;
    p_tmp->p_next = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_mid == &(p_link->tail)) {
            p_first->p_next = p_tmp;
            p_tmp->p_next = p_mid;
            break;
        }
    }
}
//按顺序加入数字的函数
void link_insert_in_order(link *p_link, int num) {
    node *p_node = NULL;
    node *p_tmp = (node *)malloc(sizeof(node));
    if (!p_tmp) {
        return ;
    }
    p_tmp->num = num;
    p_tmp->p_next = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_mid == &(p_link->tail) || p_mid->num > num) {
            p_first->p_next = p_tmp;
            p_tmp->p_next = p_mid;
            break;
        }
    }
}
//删除最前边数字的函数
void link_remove_head(link *p_link) {
    node *p_first = NULL, *p_mid = NULL, *p_last = NULL;
    p_first = &(p_link->head);
    p_mid = p_first->p_next;
    p_last = p_mid->p_next;
    p_first->p_next = p_last;
    free(p_mid);
    p_mid = NULL;
}
//删除最后一个结点的函数
void link_remove_tail(link *p_link) {
    node *p_node = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_last == &(p_link->tail)) {
            p_first->p_next = p_last;
            free(p_mid);
            p_mid = NULL;
            break;
        }
    }
}
//获得最前面数字的函数
int link_get_head(const link *p_link, int *p_num) {
    if (p_link->head.p_next == &(p_link->tail)) {
        return 0;
    }
    else {
        *p_num = p_link->head.p_next->num;
        return 1;
    }
}
//获得最后一个数字的函数
int link_get_tail(link *p_link, int *p_num) {
    node *p_node = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_last == &(p_link->tail)) {
            *p_num = p_mid->num;
            return 1;
        }
    }
    return 0;
}






/*
    链表测试
*/
#include <stdio.h>
#include "04link.h"
int main() {
    int num = 0;
    node *p_node = NULL;
    link lnk = {0};
    link_init(&lnk);
    link_add_head(&lnk, 10);
    link_append(&lnk, 100);
    link_insert_in_order(&lnk, 70);
    link_insert_in_order(&lnk, 20);
    link_insert_in_order(&lnk, 40);
    link_insert_in_order(&lnk, 30);
    link_insert_in_order(&lnk, 50);
    printf("数字个数是%d
", link_size(&lnk));
    for (p_node = &(lnk.head);p_node != &(lnk.tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_mid != &(lnk.tail)) {
            printf("%d ", p_mid->num);
        }
    }
    printf("
");
    link_remove_head(&lnk);
    link_remove_tail(&lnk);
    link_get_head(&lnk, &num);
    printf("最前边的数字是%d
", num);
    link_get_tail(&lnk, &num);
    printf("最后边的数字是%d
", num);
    printf("数字个数是%d
", link_size(&lnk));
    for (p_node = &(lnk.head);p_node != &(lnk.tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_mid != &(lnk.tail)) {
            printf("%d ", p_mid->num);
        }
    }
    printf("
");
    link_deinit(&lnk);
    return 0;
}

/*
    链表演示
*/
#ifndef    __01LINK_H__
#define    __01LINK_H__
typedef struct node {
    int num;
    struct node *p_next;
    struct node *p_prev;
} node;
typedef struct {
    node head, tail;
    node *p_cur;
} link;
//初始化函数
void link_init(link *);
//清理函数
void link_deinit(link *);
//获得有效数字个数的函数
int link_size(const link *);
//在链表头加入数字
void link_add_head(link *, int );
//在链表末尾追加数字
void link_append(link *, int );
//按顺序加入数字的函数
void link_insert_in_order(link *, int );
//删除最前边数字的函数
void link_remove_head(link *);
//删除最后一个结点的函数
void link_remove_tail(link *);
//获得最前面数字的函数
int link_get_head(const link *, int *);
//获得最后一个数字的函数
int link_get_tail(const link *, int *);
//开始从前向后遍历所有结点
void link_begin(link *);
//在遍历中获得下一个结点的数字
int link_next(link *, int *);
//开始从后向前遍历所有结点
void link_rbegin(link *);
//获得前一个数字的函数
int link_prev(link *, int *);
#endif   //__01LINK_H__





/*
    链表演示
*/
#include <stdlib.h>
#include "01link.h"
//初始化函数
void link_init(link *p_link) {
    p_link->head.p_next = &(p_link->tail);
    p_link->tail.p_next = NULL;
    p_link->tail.p_prev = &(p_link->head);
    p_link->head.p_prev = NULL;
    p_link->p_cur = NULL;
}
//清理函数
void link_deinit(link *p_link) {
    while (p_link->head.p_next != &(p_link->tail)) {
        node *p_first = &(p_link->head);
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        p_first->p_next = p_last;
        p_last->p_prev = p_first;
        free(p_mid);
        p_mid = NULL;
    }
    p_link->p_cur = NULL;
}
//获得有效数字个数的函数
int link_size(const link *p_link) {
    int cnt = 0;
    const node *p_node = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        const node *p_first = p_node;
        const node *p_mid = p_first->p_next;
        const node *p_last = p_mid->p_next;
        if (p_mid != &(p_link->tail)) {
            cnt++;
        }
    }
    return cnt;
}
//在链表头加入数字
void link_add_head(link *p_link, int num) {
    node *p_first = NULL, *p_mid = NULL, *p_last = NULL;
    node *p_tmp = (node *)malloc(sizeof(node));
    if (!p_tmp) {
        return ;
    }
    p_tmp->num = num;
    p_tmp->p_next = NULL;
    p_tmp->p_prev = NULL;
    p_first = &(p_link->head);
    p_mid = p_first->p_next;
    p_last = p_mid->p_next;
    p_first->p_next = p_tmp;
    p_tmp->p_prev = p_first;
    p_tmp->p_next = p_mid;
    p_mid->p_prev = p_tmp;
    p_link->p_cur = NULL;
}
//在链表末尾追加数字
void link_append(link *p_link, int num) {
    node *p_first = NULL, *p_mid = NULL, *p_last = NULL;
    node *p_tmp = (node *)malloc(sizeof(node));
    if (!p_tmp) {
        return ;
    }
    p_tmp->num = num;
    p_tmp->p_next = NULL;
    p_tmp->p_prev = NULL;
    p_first = p_link->tail.p_prev;
    p_mid = p_first->p_next;
    p_last = p_mid->p_next;
    p_first->p_next = p_tmp;
    p_tmp->p_prev = p_first;
    p_tmp->p_next = p_mid;
    p_mid->p_prev = p_tmp;
    p_link->p_cur = NULL;
}
/*void link_append(link *p_link, int num) {
    node *p_tmp = (node *)malloc(sizeof(node));
    node *p_node = NULL;
    if (!p_tmp) {
        return ;
    }
    p_tmp->num = num;
    p_tmp->p_next = NULL;
    p_tmp->p_prev = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_mid == &(p_link->tail)) {
            p_first->p_next = p_tmp;
            p_tmp->p_prev = p_first;
            p_tmp->p_next = p_mid;
            p_mid->p_prev = p_tmp;
            break;
        }
    }
    p_link->p_cur = NULL;
}*/
//按顺序加入数字的函数
void link_insert_in_order(link *p_link, int num) {
    node *p_node = NULL;
    node *p_tmp = (node *)malloc(sizeof(node));
    if (!p_tmp) {
        return ;
    }
    p_tmp->num = num;
    p_tmp->p_next = NULL;
    p_tmp->p_prev = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_mid == &(p_link->tail) || p_mid->num > num) {
            p_first->p_next = p_tmp;
            p_tmp->p_prev = p_first;
            p_tmp->p_next = p_mid;
            p_mid->p_prev = p_tmp;
            break;
        }
    }
    p_link->p_cur = NULL;
}
//删除最前边数字的函数
void link_remove_head(link *p_link) {
    node *p_first = NULL, *p_mid = NULL, *p_last = NULL;
    p_first = &(p_link->head);
    p_mid = p_first->p_next;
    p_last = p_mid->p_next;
    p_first->p_next = p_last;
    p_last->p_prev = p_first;
    free(p_mid);
    p_mid = NULL;
    p_link->p_cur = NULL;
}
//删除最后一个结点的函数
void link_remove_tail(link *p_link) {
    if (p_link->head.p_next != &(p_link->tail)) {
        node *p_first = p_link->tail.p_prev->p_prev;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        p_first->p_next = p_last;
        p_last->p_prev = p_first;
        free(p_mid);
        p_mid = NULL;
    }
    p_link->p_cur = NULL;
}
/*void link_remove_tail(link *p_link) {
    node *p_node = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_last == &(p_link->tail)) {
            p_first->p_next = p_last;
            p_last->p_prev = p_first;
            free(p_mid);
            p_mid = NULL;
            break;
        }
    }
    p_link->p_cur = NULL;
}*/
//获得最前面数字的函数
int link_get_head(const link *p_link, int *p_num) {
    if (p_link->head.p_next == &(p_link->tail)) {
        return 0;
    }
    else {
        *p_num = p_link->head.p_next->num;
        return 1;
    }
}
//获得最后一个数字的函数
int link_get_tail(const link *p_link, int *p_num) {
    if (p_link->head.p_next == &(p_link->tail)) {
        return 0;
    }
    else {
        *p_num = p_link->tail.p_prev->num;
        return 1;
    }
}
/*int link_get_tail(const link *p_link, int *p_num) {
    node *p_node = NULL;
    for (p_node = &(p_link->head);p_node != &(p_link->tail);p_node = p_node->p_next) {
        node *p_first = p_node;
        node *p_mid = p_first->p_next;
        node *p_last = p_mid->p_next;
        if (p_last == &(p_link->tail)) {
            *p_num = p_mid->num;
            return 1;
        }
    }
    return 0;
}*/
//开始从前向后遍历所有结点
void link_begin(link *p_link) {
    p_link->p_cur = &(p_link->head);
}
//在遍历过程中获得下一个数字
int link_next(link *p_link, int *p_num) {
    if (!(p_link->p_cur)) {
        return 0;
    }
    p_link->p_cur = p_link->p_cur->p_next;
    if (p_link->p_cur == &(p_link->tail)) {
        p_link->p_cur = NULL;
        return 0;
    }
    else {
        *p_num = p_link->p_cur->num;
        return 1;
    }
}
//开始从后向前依次遍历链表中所有结点
void link_rbegin(link *p_link) {
    p_link->p_cur = &(p_link->tail);
}
//在从后先前遍历过程中获得前一个数字
int link_prev(link *p_link, int *p_num) {
    if (!(p_link->p_cur)) {
        return 0;
    }
    p_link->p_cur = p_link->p_cur->p_prev;
    if (p_link->p_cur == &(p_link->head)) {
        return 0;
    }
    else {
        *p_num = p_link->p_cur->num;
        return 1;
    }
}





/*
    链表测试
*/
#include <stdio.h>
#include "01link.h"
int main() {
    int num = 0;
    link lnk = {0};
    link_init(&lnk);
    link_add_head(&lnk, 10);
    link_append(&lnk, 100);
    link_insert_in_order(&lnk, 70);
    link_insert_in_order(&lnk, 20);
    link_insert_in_order(&lnk, 40);
    link_insert_in_order(&lnk, 30);
    link_insert_in_order(&lnk, 50);
    printf("数字个数是%d
", link_size(&lnk));
    link_begin(&lnk);
    while (1) {
       if (link_next(&lnk, &num)) {
           printf("%d ", num);
       }
       else {
           break;
       }
    }
    printf("
");
    link_remove_head(&lnk);
    link_remove_tail(&lnk);
    link_get_head(&lnk, &num);
    printf("最前边的数字是%d
", num);
    link_get_tail(&lnk, &num);
    printf("最后边的数字是%d
", num);
    printf("数字个数是%d
", link_size(&lnk));
    link_begin(&lnk);
    while (1) {
       if (link_next(&lnk, &num)) {
           printf("%d ", num);
       }
       else {
           break;
       }
    }
    printf("
");
    link_rbegin(&lnk);
    while (1) {
        if (link_prev(&lnk, &num)) {
            printf("%d ", num);
        }
        else {
            break;
        }
    }
    printf("
");
    link_deinit(&lnk);
    return 0;
}