#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct student_info {
    char name[10];
    int height;
    float weight;
} element;

typedef struct ListNode {     // 노드 타입을 구조체로 정의한다.
    element data;
    struct ListNode* link;
} ListNode;

ListNode* insert_first(ListNode* head, element value)
{
    ListNode* p = (ListNode*)malloc(sizeof(ListNode));//(1)
    p->data = value;    // (2)
    p->link = head; //(3)
    head = p; //(4)

    return head;
}

// 노드 pre 뒤에 새로운 노드 삽입
ListNode* insert(ListNode* head, ListNode* pre, element value)
{
    ListNode* p = (ListNode*)malloc(sizeof(ListNode));    //(1)
    p->data = value;        //(2)
    p->link = pre->link;    //(3)    
    pre->link = p;        //(4)    
    return head;        //(5)    
}

ListNode* delete_first(ListNode* head)
{
    ListNode* removed;
    if (head == NULL) return NULL;
    removed = head;    // (1)
    head = removed->link;    // (2)
    free(removed);        // (3)
    return head;        // (4)
}

// pre가 가리키는 노드의 다음 노드를 삭제한다. 
ListNode* delete(ListNode* head, ListNode* pre)
{
    ListNode* removed;
    removed = pre->link;
    pre->link = removed->link;        // (2)
    free(removed);            // (3)
    return head;            // (4)
}

void print_list(ListNode* head)
{
    for (ListNode* p = head; p != NULL; p = p->link)
        printf("(%s %3d %4.1f)->", p->data.name, p->data.height, p->data.weight);
    printf("\n");
}

element* new_element(char* name, int height, float weight)
{
    element* p = (element*)malloc(sizeof(element));    //(1)
    strcpy(p->name, name);
    p->height = height;
    p->weight = weight;

    return p;
}

ListNode* find_node(ListNode* head, char* name)
{
    for (ListNode* p = head; p != NULL; p = p->link)
        if (!strcmp(p->data.name, name))
            return p;
    return NULL;
}

ListNode* insert_last(ListNode* head, element value)
{
    ListNode* p = (ListNode*)malloc(sizeof(ListNode));
    ListNode* t;
    p->data = value;

    if (head == NULL) {
        p->link = head;
        head = p;
    }
    else {
        for (t = head; t->link != NULL; t = t->link);
        t->link = p;
        p->link = NULL;
    }

    return head;
}

ListNode* insert_multiple_after_node(ListNode* head, char* name, int k)
{
    ListNode* find = find_node(head, name);
    element* new = find;
    if (find != NULL)
    {
        for (int i = 0; i < k; i++)
        {
            head = insert(head, find, *new);
        }
    }
    
    return head;
}

// 테스트 프로그램
int main(void)
{
    ListNode* head = NULL, * pre;
    element* new;

    new = new_element("홍길동", 167, 72.5);
    head = insert_first(head, *new);
    new = new_element("유관순", 163, 58.4);
    head = insert_first(head, *new);
    new = new_element("김유신", 159, 70.8);
    head = insert_first(head, *new);
    print_list(head);

    head = delete_first(head);
    print_list(head);

    pre = find_node(head, "유관순");
    if (pre != NULL) {
        new = new_element("이순신", 172, 83.4);
        head = insert(head, pre, *new);
    }
    print_list(head);

    pre = find_node(head, "이순신");
    if (pre != NULL) {
        head = delete(head, pre);
        print_list(head);
    }
    new = new_element("홍길동", 167, 72.5);
    head = insert_last(head, *new);
    print_list(head);

    new = new_element("김유신", 159, 70.8);
    head = insert_first(head, *new);
    print_list(head);

    head = insert_multiple_after_node(head, "유관순", 3);
    print_list(head);

    head = insert_multiple_after_node(head, "이순신", 3);
    print_list(head);

    return 0;
}