5월 15일 더블 링크드 문제

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#pragma warning(disable: 4996)
 
typedef struct _list List;
 
struct _list {
    int key;
    struct _list *prev;
    struct _list *next;
};
List *head, *tail;
 
/*
 
head와 tail 사이에 노드를
정렬삽입, 검색후삭제,
모든 노드출력(head->tail버젼, tail->head버젼)하는 함수를 완성하시오
 
*/
 
void init_list(void)
{
    head = (List*)malloc(sizeof(List)); //왼쪽 기둥
    tail = (List*)malloc(sizeof(List)); //오른쪽 기둥
    head->next = tail;
    head->prev = head;
    tail->next = tail;
    tail->prev = head;
    head->key = 999;
    tail->key = 111;
}
 
void insert_List(int data) // 
{
    List *nw = (List*)malloc(sizeof(List));
    nw->key = data;
    List *wk;
    wk = head->next;
    if (head->next == tail)
    {
 
        nw->prev = head;
        head->next = nw;
        nw->next = tail;
        tail->prev = nw;
    }
    else
    {
        if (head->next->key >= data)
        {
            nw->prev = head;
            nw->next = head->next;
            head->next->prev = nw;
            head->next = nw;
        }
        else
        {
            while (wk->key <= data && wk != tail)
            {
                wk = wk->next;
            }
 
            if (wk->next != NULL)
            {
 
                wk = wk->prev; printf("현재 워크 위치  %d\n", wk->key);
                nw->prev = wk;
                nw->next = wk->next;
                wk->next->prev = nw;
                wk->next = nw;
            }
            else
            {
                printf("else문 현재 워크 위치  %d\n", wk->key);
                nw->prev = wk;
                nw->next = wk->next;
                wk->next->prev = nw;
                wk->next = nw;
            }
        }
    }
 
}
 
void print_List(void)
{
    List *wk;
    wk = head->next;
    printf("==head->tail 방향==\n");
    while (wk != tail)
    {
        printf("%d\t", wk->key);
        wk = wk->next;
    }
    printf("\n---------------------------------------------------------------------------------------------------\n");
    printf("==tail->head 방향==\n");
 
    while (wk->prev != head)
    {
        wk = wk->prev;
        printf("%d\t", wk->key);
    }
    printf("\n---------------------------------------------------------------------------------------------------\n");
}
 
void delete_List(int data)
{
    List *wk;
    wk = head;
    while (wk->next->key != data && wk->next != tail)
    {
        wk = wk->next;
    }
 
    if (wk->next != tail)// 중간에 찾음
    {
        List* kill = wk->next;
        printf("wk 위치 확인%d\n", wk->key);
        wk->next = kill->next;
        kill->next->prev = wk;
        free(kill);
    }
 
    else
    {
        printf("삭제하려는 데이터가 존재하지 않습니다.\n");
    }
}
int main()
{
    
    int num;
    init_list();
 
    int cnt=0;
    while (cnt < 10)
    {
    printf("삽입 할 데이터 입력:");
    scanf("%d", &num);
    insert_List(num);
    print_List();
    cnt++;
    }
    cnt = 0;
 
    while (cnt < 10)
    {
    printf("삭제 할 데이터 입력:");
    scanf("%d", &num);
    delete_List(num);
    print_List();
    }
}