[DS]Stack 實作 by C

最近看論文陷入一個瓶頸，感覺還是寫code實際，
突然想到很久沒有寫看看基本的資料結構了，所以決定回頭用C寫個stack，
順便複習一下指標的用法。

#include<stdio.h>
#include<stdlib.h>

typedef struct node{
        char data1;
        struct node *Link;
}NODE;

NODE* initSteak(NODE *top){
        top = NULL;
        return top;
}

NODE* pushSteak(NODE* top, char data){
        NODE *newBlock;
        newBlock = (NODE*)malloc(sizeof(NODE));
        newBlock->data1 = data;
        newBlock->Link = top;
        top = newBlock;
        return top;
}

NODE* popSteak(NODE *top){
        NODE *tmpBlock = top;
        top = top->Link;
        free(tmpBlock);
        return top;
}

void listSteak(NODE *top){
        while(!isEmpty(top)){
                printf("%c ", top->data1);
                top = top->Link;
        }
        printf("\n");
}

int isEmpty(NODE* top){
        return (top == NULL);
}

int main(){
        NODE *node;
        node = initSteak(node);

        node = pushSteak(node, 'a');
        node = pushSteak(node, 'b');
        listSteak(node);
        node = popSteak(node);
        listSteak(node);
        node = pushSteak(node, 'c');
        node = pushSteak(node, 'd');
        node = pushSteak(node, 'e');
        listSteak(node);
        node = popSteak(node);
        node = popSteak(node);
        node = popSteak(node);
        listSteak(node);
}