根据P257页例题13-8要求，编写一个链表结构，读取任意多个用户输入。之后删除学号为2017003的节点信息，并把删除后的链表打印出来

妖狐艹你老母 2022-10-05 09:46 32阅读 0赞

#define _CRT_SECURE_NO_WARNINGS
    #include <stdio.h>
    #include <malloc.h>
    #include <stdlib.h>
    
    typedef struct node_s {
        long num;
        float score;
        struct node_s* next;
    } node_t;
    
    int n;
    
    node_t* create()
    {
        node_t *head, *p1, *p2;
    	
    	n = 0;
        p1 = p2 = (node_t*) malloc(sizeof(node_t));
    	scanf("%ld %f", &p1->num, &p1->score);
        head = NULL;
    
        while (p1->num != 0) {
            n++;
            if (n == 1)
                head = p1;
            else
                p2->next = p1;
            p2 = p1;
            p1 = (node_t*) malloc(sizeof(node_t));
            scanf("%ld %f", &p1->num, &p1->score);
        }
        p2->next = NULL;
    
        return (head);
    }
    
    void print(node_t *head)
    {
        node_t *p;
    
        if (head == NULL) {
            return;
        }
    
        for (p = head; p != NULL; p = p->next) {
            printf("%ld %5.1f\n", p->num, p->score);
        }
    }
    
    node_t *find(node_t *head, int num)
    {
        node_t *p;
    
        if (head == NULL) {
            return NULL;
        }
    
        for (p = head; p != NULL; p = p->next) {
            if(p->num == num){
                return p;
            }
        }
    
        return NULL;
    }
    
    node_t *del(node_t *head, int num)
    {
        node_t *p1, *p2;
    
        if (head == NULL) {
    		printf("list is NULL\n");
            return head;
        }
    
        for (p1 = head; p1->next != NULL; p2=p1, p1=p1->next) {
            if(num == p1->num){
                break;
            }
        }
    
        if (num == p1->num) {
            if (p1 == head) {
                head = p1->next;
            } else {
                p2->next = p1->next;
            }
            
    		free(p1);   //书上漏了释放内存
            p1 = NULL;
            
    		n--;
    
            return head;
        } else {
    		printf("not exist: num %d\n", num);
            return head;
        }
    }
    
    node_t *insert(node_t *head, node_t *stud)
    {
        node_t *p0, *p1, *p2;
    
        p1 = head;
        p0 = stud;
    
    	//创建首节点
        if (head == NULL) {
            head = p0;
            p0->next = NULL;
            n++;
            return head;
        }
    
    	//找到插入位置
        for (p1 = head; p1->next != NULL; p2=p1, p1 = p1->next) {
            if(p0->num < p1->num) {
                break;
            }
        }
    
        if (p0->num <= p1->num) { 
            if (p1 == head) {	//找到插入位置，插入队首
                head = p0;
    			p0->next = p1;
            } else {	//找到插入位置，插入队列中间位置
                p2->next = p0;
                p0->next = p1;
            }
        } else {//找不到插入位置，插入队尾
            p1->next = p0;
            p0->next = NULL;
        }
    
        n++;
    
        return head;
    }
    
    //输出
    void test_14_1(void)
    {
        node_t* head;
    
        head = create();
        print(head);
    }
    
    //查找
    void test_14_2(void)
    {
        node_t* head;
        node_t* ret;
    
        head = create();
        ret = find(head, 2017003);
        if (ret) {
            printf("%ld %0.1f\n", ret->num, ret->score);
        } else {
            printf("%p\n", ret);
        }
    }
    
    //插入
    node_t* test_14_3(void)
    {
        node_t* head;
        node_t* stud;
    
        head = create();
    
        //插入头部
        stud = (node_t*) malloc(sizeof(node_t));
        stud->num = 2017000;
        stud->score = 85.0;
        head = insert(head, stud);
    
        //插入中间
        stud = (node_t*) malloc(sizeof(node_t));
        stud->num = 2017006;
        stud->score = 85.0;
        head = insert(head, stud);
    
        //插入尾部
        stud = (node_t*) malloc(sizeof(node_t));
        stud->num = 2017013;
        stud->score = 85.0;
        head = insert(head, stud);
    
        print(head);
    
    	return head;
    }
    
    //删除
    void test_14_4(void)
    {
        node_t* head;
    
        head = create();
    	head = del(head, 2017001);
    	printf("delete num %d\n", 2017001);
    	head = del(head, 2017005);
    	printf("delete num %d\n", 2017005);
    	head = del(head, 2017010);
    	printf("delete num %d\n", 2017010);
    
        print(head);
    }
    
    //删除
    void test_14_5(void)
    {
        node_t* head;
    
        head = create();
    	head = del(head, 2017003);
        print(head);
    }
    
    
    #define T5
    /*
    2017001 81.0
    2017002 82.0
    2017003 83.0
    2017004 84.0
    2017005 85.0
    2017010 85.0
    0 0
    */
    
    int main(void)
    {
    #ifdef T1
        test_14_1();
    #elif defined(T2)
        test_14_2();
    #elif defined(T3)
        test_14_3();
    #elif defined(T4)
        test_14_4();
    #elif defined(T5)
        test_14_5();
    #endif
    	//system("pause");
    }

输入

2017001 81.0  
2017002 82.0  
2017003 83.0  
2017004 84.0  
2017005 85.0  
2017010 85.0  
0 0

输出

2017001 81.0  
2017002 82.0  
2017004 84.0  
2017005 85.0  
2017010 85.0