数据结构与算法-链表

链表
    包含一个线性链式存储结构和一组相关的操作函数;
    链表的基本功能包括:插入/删除和遍历;

/* * 04linklist.h */#ifndef __04LINKLIST_H__#define __04LIKKLIST_H__typedef struct node{    int num;    struct node *p_next;} node;void init();void deinit();int empty();void insert_head(int);void remove_head();void insert_tail(int);void remove_tail();int get_head();int get_tail();int size();void for_each(int(*)(void*,void*),void*);#endif //__04LINKLIST_H__

/* * 链表演示 * 04linklist.c */#include <stdio.h>#include <stdlib.h>#include "04linklist.h"static node head;/* 初始化函数 */void init() {    head.p_next = NULL;}/* 清理函数 */void deinit() {            //不断的删除一节点    while (head.p_next) {        node *p_tmp = head.p_next;        head.p_next = p_tmp->p_next;        free(p_tmp);        p_tmp = NULL;    }}/* 判断空的函数 */int empty() {    return !(head.p_next);}/* 插入一节点 */void insert(int num) {    node *p_tmp = (node *) malloc(sizeof(node));    if (p_tmp) {        p_tmp->num = num;        p_tmp->p_next = head.p_next;        head.p_next = p_tmp;    }}/* 删除一节点 */void remove_head() {    if (head.p_next) {        node *p_tmp = head.p_next;        head.p_next = p_tmp->p_next;        free(p_tmp);        p_tmp = NULL;    }}/* 插入尾节点 */void insert_tail(int num) {    node *p_tmp = (node *) malloc(sizeof(node)), *p_node = NULL;    if (p_tmp) {        p_tmp->num = num;        p_tmp->p_next = NULL;        for (p_node = &head; p_node; p_node = p_node->p_next) {            if (!(p_node->p_next)) {    //将新节点插入到尾部                p_node->p_next = p_tmp;                break;            }        }    }}/* 删除尾节点 */void remove_tail() {    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_node->p_next && !(p_node->p_next->p_next)) {            free(p_node->p_next);            p_node->p_next = NULL;        }    }}/* 获得一节点的内容 */int get_head() {    int ret = 1 << 31;    if (head.p_next) {        ret = head.p_next->num;    }    return ret;}/* 获得尾节点的内容 */int get_tail() {    int ret = 1 << 31;    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_node->p_next && !(p_node->p_next->p_next)) {            ret = p_node->p_next->num;            break;        }    }    return ret;}/* 获得有效数据的个数 */int size() {    int cnt = 0;    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_node->p_next) {            cnt++;        }    }    return cnt;}/*void print(){    node *p_node = NULL;    for(p_node = &head;p_node;p_node = p_node->p_next){        if(p_node->p_next){            printf("%d ",p_node->p_next->num);        }    }    printf("\n");}*//* 遍历函数(用函数指针)回调函数 */void for_each(int (*p_func) (void *, void *), void *p_data) {    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_func(p_node, p_data)) {            break;        }    }}

/* * 链表测试 * 04main.c */#include <stdio.h>#include "04linklist.h"int print_cb(void *p_node, void *p_data) {    //print call back函数    if (((node *) p_node)->p_next) {        printf("%d ", ((node *) p_node)->p_next->num);        if (!(((node *) p_node)->p_next->p_next)) {            printf("\n");            return 1;        }    }    return 0;}int main() {    init();    insert_tail(1);    insert_tail(2);    insert_tail(3);    printf("有效数据个数是%d\n", size());    for_each(print_cb, NULL);    printf("%d ", get_tail());    remove_tail();    printf("%d ", get_tail());    remove_tail();    printf("%d\n", get_tail());    remove_tail();    printf(empty()? "空的\n" : "非空\n");    deinit();    return 0;}

练习
    编写函数从链表中删除指定数字,用返回值表示操作结果(1表示成功,0表示失败);

/* * 05linklist.h */#ifndef __05LINKLIST_H__#define __05LIKKLIST_H__typedef struct node{    int num;    struct node *p_next;} node;void init();void deinit();int empty();void insert_head(int);void remove_head();void insert_tail(int);void remove_tail();int get_head();int get_tail();int size();void for_each(int(*)(void*,void*),void*);int remove_node(int);#endif //__05LINKLIST_H__

/* * 链表演示 * 05linklist.c *///#include <stdio.h>#include <stdlib.h>#include "05linklist.h"static node head;/* 初始化函数 */void init() {    head.p_next = NULL;}/* 清理函数 */void deinit() {            //不断的删除一节点    while (head.p_next) {        node *p_tmp = head.p_next;        head.p_next = p_tmp->p_next;        free(p_tmp);        p_tmp = NULL;    }}/* 判断空的函数 */int empty() {    return !(head.p_next);}/* 插入一节点 */void insert(int num) {    node *p_tmp = (node *) malloc(sizeof(node));    if (p_tmp) {        p_tmp->num = num;        p_tmp->p_next = head.p_next;        head.p_next = p_tmp;    }}/* 删除一节点 */void remove_head() {    if (head.p_next) {        node *p_tmp = head.p_next;        head.p_next = p_tmp->p_next;        free(p_tmp);        p_tmp = NULL;    }}/* 插入尾节点 */void insert_tail(int num) {    node *p_tmp = (node *) malloc(sizeof(node)), *p_node = NULL;    if (p_tmp) {        p_tmp->num = num;        p_tmp->p_next = NULL;        for (p_node = &head; p_node; p_node = p_node->p_next) {            if (!(p_node->p_next)) {    //将新节点插入到尾部                p_node->p_next = p_tmp;                break;            }        }    }}/* 删除尾节点 */void remove_tail() {    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_node->p_next && !(p_node->p_next->p_next)) {            free(p_node->p_next);            p_node->p_next = NULL;        }    }}/* 获得一节点的内容 */int get_head() {    int ret = 1 << 31;    if (head.p_next) {        ret = head.p_next->num;    }    return ret;}/* 获得尾节点的内容 */int get_tail() {    int ret = 1 << 31;    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_node->p_next && !(p_node->p_next->p_next)) {            ret = p_node->p_next->num;            break;        }    }    return ret;}/* 获得有效数据的个数 */int size() {    int cnt = 0;    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_node->p_next) {            cnt++;        }    }    return cnt;}/*void print(){    node *p_node = NULL;    for(p_node = &head;p_node;p_node = p_node->p_next){        if(p_node->p_next){            printf("%d ",p_node->p_next->num);        }    }    printf("\n");}*//* 遍历函数(用函数指针)回调函数 */void for_each(int (*p_func) (void *, void *), void *p_data) {    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_func(p_node, p_data)) {            break;        }    }}/*//删除一个指定的数字 int remove_node(int num){    node *p_node = NULL;    for(p_node = &head;p_node;p_node = p_node->p_next){        if(p_node->p_next && p_node->p_next->num == num){            node *p_tmp = p_node->p_next;            p_node->p_next = p_node->p_next->p_next;            free(p_tmp);            p_tmp = NULL;            return 1;        }    }    return 0;}*//* 删除指定数字callback */typedef struct rdata {    int num, ret;} rdata;int remove_cb(void *p_node, void *p_data) {    if (((node *) p_node)->p_next        && (((node *) p_node)->p_next)->num == ((rdata *) p_data)->num) {        node *p_tmp = ((node *) p_node)->p_next;        ((node *) p_node)->p_next = ((node *) p_node)->p_next->p_next;        free(p_tmp);        p_tmp = NULL;        ((rdata *) p_data)->ret = 1;        return 1;    }    return 0;}int remove_node(int num) {    rdata rd = { };    rd.num = num;    for_each(remove_cb, &rd);    return rd.ret;}

/* * 链表测试 * 05main.c */#include <stdio.h>#include "05linklist.h"int print_cb(void *p_node, void *p_data) {    //print call back函数    if (((node *) p_node)->p_next) {        printf("%d ", ((node *) p_node)->p_next->num);        if (!(((node *) p_node)->p_next->p_next)) {            printf("\n");            return 1;        }    }    return 0;}int main() {    init();    insert_tail(1);    insert_tail(2);    insert_tail(3);    printf("有效数据个数是%d\n", size());    for_each(print_cb, NULL);    printf("%d ", get_tail());    printf("\n删除操作返回%d\n", remove_node(1));    for_each(print_cb, NULL);    printf("%d ", get_tail());    remove_tail();    printf("%d\n", get_tail());    remove_tail();    printf(empty()? "空的\n" : "非空\n");    deinit();    return 0;}

/* * data.h */#ifndef __DATA_H__#define __DATA_H__typedef struct node {    int id;    struct node *p_next;} node, *ll_head;ll_head ll_create(void); /* create a linked list */node *ll_input(node *);void ll_insert(ll_head, node *); /* insert a node to the linked list */void ll_delete(ll_head, node *); /* delete a node from the linked list */node *ll_locate(ll_head, int); /* return if the node exists */void ll_free(ll_head); /* free memory */void ll_traversal(ll_head); /* traversal the linked list */#endif /* __DATA_H__*/

/* * data.c */#include <stdio.h>#include <stdlib.h>#include "data.h"/* create a linked list */ll_head ll_create(void) {    node *new = malloc(sizeof(struct node));    if (new == NULL) {        perror("malloc");        return NULL;    }    new->p_next = NULL;    //printf("create linked list successfully !\n");    return new;}/* insert a node to the linked list */void ll_insert(ll_head head, node * tmp) {    if (ll_locate(head, tmp->id)) {        printf("the id(%d) has exited\n", tmp->id);        return;    }    node *new = malloc(sizeof(struct node));    if (new == NULL) {        perror("malloc");        return;    }    new->id = tmp->id;    new->p_next = NULL;    node *this = head;    for (this = head; this; this = this->p_next) {        /* insert id to link list in order */        if (this->p_next == NULL) {            this->p_next = new;            break;        } else if (this->p_next->id > tmp->id) {            new->p_next = this->p_next;            this->p_next = new;            break;        }    }}/* delete a node from the linked list */void ll_delete(ll_head head, node * tmp) {    node *this = head;    node *fro = this;    int flag = 0;    for (; this;) {        fro = this;        this = this->p_next;        if (this->id == tmp->id) {            fro->p_next = this->p_next;            free(this);            this = fro;            flag = 1;            printf("delete id(%d)\n", tmp->id);        }    }    if (this == NULL && flag == 0) {        printf("the node not exists\n");    }}/* free the memory of the linkedlist */void ll_free(ll_head head) {    node *fro = head;    node *this = head;    for (; this->p_next;) {        fro = this;        this = this->p_next;        fro->p_next = this->p_next;        //printf("free(%02d,%02d) ", this->x, this->y);        free(this);        this = fro;    }    //printf("\n");}/* return if the node exists */node *ll_locate(ll_head head, int id) {    node *this = head;    while (this = this->p_next) {        if (this->id == id) {            return this;        }    }    return NULL;}/* traversal the linked list */void ll_traversal(ll_head head) {    node *this = head;    while (this = this->p_next) {        printf("%d\n", this->id);    }}

/* * 按顺序插入用户输入的数据不超过10000个 * 直到用户输入0时结束; * user.c * */#include <stdio.h>#include <stdlib.h>#include "data.h"int main() {    node *ll_head = ll_create();    node tmp;    int num = 0;    while (num++ <= 10000) {        printf("please input a num: ");        scanf("%d", &tmp.id);        if (tmp.id == 0) {            break;        }        printf("id = %d\n", tmp.id);        ll_insert(ll_head, &tmp);    //插入    }    ll_traversal(ll_head);    //遍历链表,顺序打印    ll_free(ll_head);    //释放空间    return 0;}

作业
    给链表增加按顺序插入的函数;
    使用遍历函数加返回值;

/* * 07linklist.h */#ifndef __07LINKLIST_H__#define __07LIKKLIST_H__typedef struct node {    int num;    struct node *p_next;} node;void init();void deinit();int empty();void insert_head(int);void remove_head();void insert_tail(int);void remove_tail();int get_head();int get_tail();int size();void for_each(int (*)(void *, void *), void *);int insert_in_order(int);#endif //__07LINKLIST_H__

/* * 链表演示 * 07linklist.c */#include <stdio.h>#include <stdlib.h>#include "07linklist.h"static node head;/* 初始化函数 */void init() {    head.p_next = NULL;}/* 清理函数 */void deinit() {    /* 不断的删除一节点 */    while (head.p_next) {        node *p_tmp = head.p_next;        head.p_next = p_tmp->p_next;        free(p_tmp);        p_tmp = NULL;    }}/* 判断空的函数 */int empty() {    return !(head.p_next);}/* 插入一节点 */void insert(int num) {    node *p_tmp = (node *) malloc(sizeof(node));    if (p_tmp) {        p_tmp->num = num;        p_tmp->p_next = head.p_next;        head.p_next = p_tmp;    }}/* 删除一节点 */void remove_head() {    if (head.p_next) {        node *p_tmp = head.p_next;        head.p_next = p_tmp->p_next;        free(p_tmp);        p_tmp = NULL;    }}/* 插入尾节点 */void insert_tail(int num) {    node *p_tmp = (node *) malloc(sizeof(node)), *p_node = NULL;    if (p_tmp) {        p_tmp->num = num;        p_tmp->p_next = NULL;        for (p_node = &head; p_node; p_node = p_node->p_next) {            if (!(p_node->p_next)) {    //将新节点插入到尾部                p_node->p_next = p_tmp;                break;            }        }    }}/* 删除尾节点 */void remove_tail() {    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_node->p_next && !(p_node->p_next->p_next)) {            free(p_node->p_next);            p_node->p_next = NULL;        }    }}/* 获得一节点的内容 */int get_head() {    int ret = 1 << 31;    if (head.p_next) {        ret = head.p_next->num;    }    return ret;}/* 获得尾节点的内容 */int get_tail() {    int ret = 1 << 31;    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_node->p_next && !(p_node->p_next->p_next)) {            ret = p_node->p_next->num;            break;        }    }    return ret;}/* 获得有效数据的个数 */int size() {    int cnt = 0;    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_node->p_next) {            cnt++;        }    }    return cnt;}/*void print(){    node *p_node = NULL;    for(p_node = &head;p_node;p_node = p_node->p_next){        if(p_node->p_next){            printf("%d ",p_node->p_next->num);        }    }    printf("\n");}*//* 遍历函数(用函数指针)回调函数 */void for_each(int (*p_func) (void *, void *), void *p_data) {    node *p_node = NULL;    for (p_node = &head; p_node; p_node = p_node->p_next) {        if (p_func(p_node, p_data)) {            break;        }    }}/* 按顺序插入 *//*int insert_in_order(int num){    node *p_node = NULL;    for (p_node = &head;p_node;p_node = p_node->p_next){        node *p_tmp = p_node->p_next;        if (!p_tmp || p_tmp->num>num){            node *p_tmp1 = (node*)malloc(sizeof(node));            if(p_tmp1){                p_tmp1->num = num;                p_tmp1->p_next = NULL;                p_tmp1->p_next = p_tmp;                p_node->p_next = p_tmp1;                return 1;            }        }    }    return 0;}*/typedef struct rdata {    int num, ret;} rdata;int insert_cb(void *p_node, void *p_data) {    node *p_tmp = ((node *) p_node)->p_next;    if (!p_tmp || p_tmp->num > ((rdata *) p_data)->num) {        node *p_tmp1 = (node *) malloc(sizeof(node));        if (p_tmp1) {            p_tmp1->num = ((rdata *) p_data)->num;            p_tmp1->p_next = NULL;            p_tmp1->p_next = p_tmp;            ((node *) p_node)->p_next = p_tmp1;            ((rdata *) p_data)->ret = 1;            return 1;        }    }    return 0;}int insert_in_order(int num) {    rdata idt = { num };    for_each(insert_cb, &idt);    return idt.ret;}

/* * 链表测试 * 07main.c */#include <stdio.h>#include "07linklist.h"int print_cb(void *p_node, void *p_data) {    /* print call back函数 */    if (((node *) p_node)->p_next) {        printf("%d ", ((node *) p_node)->p_next->num);        if (!(((node *) p_node)->p_next->p_next)) {            printf("\n");            return 1;        }    }    return 0;}int main() {    init();    insert_tail(1);    insert_tail(5);    insert_tail(9);    insert_in_order(7);    insert_in_order(13);    printf("有效数据个数是%d\n", size());    for_each(print_cb, NULL);    deinit();    return 0;}