단일 리스트로 스택 구현하기 -Stack- C 언어

1. LinkedListstack.h

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
typedef struct Node
{
    char *Data;
    struct Node* Next;
}Node;
 
typedef struct LinkedStack
{
    Node* List;
    Node* Top;
}LLS;
 
Node* LLS_CreateStack(LLS** Stack);
Node* LLS_CreateNode(char* newData);
 
void LLS_DestroyNode(Node* _Node);
 
void LLS_Push(LLS* Stack, Node* NewNode);
 
Node* LLS_Pop(LLS* Stack);
 
Node* LLS_Top(LLS* Stack);
int LLS_GetSize(LLS* Stack);
int LLS_IsEmpaty(LLS* Stack);
 
typedef LLS LinkedStack;
 
Node* LLS_CreateStack(LLS** Stack)
{
    (*Stack) = (LLS*)malloc(sizeof(LLS));
    (*Stack)->List = NULL;
    (*Stack)->Top = NULL;
}
 
Node* LLS_CreateNode(char* newData)
{
    unsigned short str_length = strlen(newData) + 1;
    Node* NewNode = (Node*)malloc(sizeof(NewNode));
    NewNode->Data = (char*)malloc(str_length);
 
    strcpy_s(NewNode->Data, str_length, newData);
 
    NewNode->Next = NULL;
 
    return NewNode;
 
}
int LLS_IsEmpaty(LLS* Stack)
{
    return (Stack->List == NULL);
}
 
void LLS_DestroyNode(Node* _Node)
{
    free(_Node->Data);
    free(_Node);
}
 
Node* LLS_Pop(LLS* Stack)
{
    //함수가 반환할 최상위 노드
    Node* TopNode = Stack->Top;
 
    if (Stack->List == Stack->Top)
    {
        Stack->List = NULL;
        Stack->Top = NULL;
    }
    else
    {
        /*새로운 최상위 노드를 스택의 Top 필드에 등록*/
        Node* CurrentTop = Stack->List;
        while (CurrentTop != NULL && CurrentTop->Next != Stack->Top)
        {
            CurrentTop = CurrentTop->Next;
        }
        Stack->Top = CurrentTop;
        CurrentTop->Next = NULL;
    }
    return TopNode;
}
 
void LLS_Push(LLS* Stack, Node* NewNode)
{
    if (Stack->List == NULL)
    {
        Stack->List = NewNode;
    }
    else
    {
        //최상위 노드를 찾아 NewNode를 쌓는다.(연결)
        Node* OldTop = Stack->List;
 
        while (OldTop->Next != NULL)
        {
            OldTop = OldTop->Next;
        }
        OldTop->Next = NewNode;
    }
    //스택의 Top 필드에 새 노드의 주소를 등록.
    Stack->Top = NewNode;
}
 
int LLS_GetSize(LLS* Stack)
{
    int Count = 0;
    Node* Current = Stack->List;
 
    while (Current != NULL)
    {
        Current = Current->Next;
        Count++;
    }
 
    return Count;
}
Node* LLS_Top(LLS* Stack)
{
    return Stack->Top;
}

2.LinkedList_Stack.c

int main(void)
{
 
    unsigned int Stack_Size = 0;
 
    LinkedStack* Stack;
    Node* Popped;
    LLS_CreateStack(&Stack);
 
    LLS_Push(Stack, LLS_CreateNode("abc"));
    LLS_Push(Stack, LLS_CreateNode("def"));
    LLS_Push(Stack, LLS_CreateNode("ghi"));
    Popped = LLS_Pop(Stack);
    Stack_Size = LLS_GetSize(Stack);
 
    printf(" Size : %d, Top :%s\n\n", Stack_Size, LLS_Top(Stack)->Data);
    
    printf("Popped : %s\n", Popped->Data);
 
    return 0;
}

3. 실행 화면