//堆疊(先進後出) – 使用鏈結(Link)實作（C
語言動態記憶體宣告）

//http://openhome.cc/Gossip/AlgorithmGossip/StackByLink.htm

#include <stdio.h>

#include <stdlib.h>

struct node {

   
int data;

   
struct node *next;

};

typedef struct node Node;

Node* creates(void);         // 建立堆疊

int isEmpty(Node*);           // 堆疊已空

int stacktop(Node*);   // 傳回頂端元素

Node* add(Node*, int);   // 新增元素

Node* delete(Node*);     // 刪除元素

void list(Node*);      // 顯示所有內容

int main(void) {

   
Node* sTop;

   
int input, select;

   
sTop = creates();

   
while(1) {

        printf(“\n\n請輸入選項(-1結束)：“);

        printf(“\n(1)插入值至堆疊“);

        printf(“\n(2)顯示堆疊頂端“);

        printf(“\n(3)刪除頂端值“);

        printf(“\n(4)顯示所有內容“);

        printf(“\n\$c>”);

        scanf(“%d”, &select);

        if(select == -1)

            break;

        switch(select) {

            case 1:

                printf(“\n輸入值：“);

                scanf(“%d”,
&input);

                sTop = add(sTop, input);

                break;

            case 2:

                printf(“\n頂端值：%d”, stacktop(sTop));

                break;

            case 3:

                sTop = delete(sTop);

                break;

            case 4:

                list(sTop);

                break;

            default:

                printf(“\n選項錯誤！“);

        }

   
}

   
printf(“\n”);

   
return 0;

}

Node* creates() {

   
return NULL;

}

int isEmpty(Node* top) {

   
return (top == NULL);

}

int stacktop(Node* top) {

   
return top->data;

}

Node* add(Node* top, int item) {

   
Node* newnode;

   
newnode = (Node*) malloc(sizeof(Node));

   
if(newnode == NULL) {

        printf(“\n記憶體配置失敗！“);

        exit(1);

   
}

   
newnode->data = item;

   
newnode->next = top;

   
top = newnode;

   
return top;

}

Node* delete(Node* top) {

   
Node* tmpnode;

   
tmpnode = top;

   
if(tmpnode == NULL) {

        printf(“\n堆疊已空！“);

        return NULL;

   
}

   
top = top->next;

   
free(tmpnode);

   
return top;

}

void list(Node* top) {

   
Node* tmpnode;

   
tmpnode = top;

   
printf(“\n
堆疊內容：“);

   
while(tmpnode != NULL) {

        printf(“%d “,
tmpnode->data);

        tmpnode = tmpnode->next;

   
}

}