단순 연결리스트의 구조체 헤드포인터 미완

#include<stdio.h> #include<stdlib.h> typedef int element; typedef struct list{ element data; struct list *link; }node; typedef struct listhead{ node *headlink; }headnode; void init(headnode *head){ head->headlink = NULL; } void error(char *sentence){ fprintf(stderr, "%s", sentence); exit(1); } void display(headnode *head){ headnode *p1 = head->headlink; if (p1!= NULL){ printf("%d->", p1->headlink ->data); display(p1->headlink->link); } printf("\n"); } node *search(node *head, element val){ node *p = head; while (p != NULL){ if (p->data == val){ return p; } } return p; } node *create_node(headnode *head, element val){ node *create_node; create_node = (node *)malloc(sizeof(node)); if (create_node == NULL){ error("MEMORY ERROR"); } create_node->link = NULL; create_node->data = val; return create_node; } void insert_node(headnode *phead, node *p, node *new_node){ if (phead == NULL){ new_node->link = NULL; phead = new_node; } else if (p == NULL){ new_node->link = phead; phead = new_node; } else{ new_node->link = p->link; p = new_node; } } /*void remove_node(headnode * phead, node *p, node * remove){ if () }*/ int main(void){ headnode list1; printf("ddd\n"); init(&list1); printf("ddd\n"); insert_node(&list1, NULL, create_node(&list1, 10)); printf("ddd\n"); /*insert_node(&list1, NULL, create_node(&list1, 10)); insert_node(&list1, NULL, create_node(&list1, 10));*/ display(&list1); printf("ddd\n"); return 0; }