C語言——鏈棧

#include<stdio.h>
#include<stdlib.h>
/*棧由節點和棧頂，棧底指針組成，節點由數據域和指向下一個節點的指針域組成，所以棧有兩個結構體*/
typedef struct node * PNode;
typedef struct node{		//定義節點的結構體 
	int data;		//數據域 
	PNode next;		//指針域 
}Node;
typedef struct stack{		//定義棧的結構體 
	PNode top;		//棧頂指針 
	int size;		//棧大小 
}Stack;
//構造一個空棧
Stack * initStack(Stack *ps){
	ps = (Stack *)malloc(sizeof(Stack));
	if(ps!=NULL){
		ps->top = NULL;
		ps->size = 0;
	}
	return ps;
} 
//判斷是否爲空棧
int isEmpty(Stack *ps){
	if(ps->top ==NULL&&ps->size==0)
		return 1;
	else
		return 0;
} 
//計算棧的大小
int GetSize(Stack *ps){
	return ps->size;
} 
//元素入棧
void push(Stack *ps,int  item){
	PNode pnode = (PNode)malloc(sizeof(Node));		//新建一個節點
	if(pnode != NULL){
		pnode->data = item;
		pnode->next = ps->top;
		ps->size++;
		ps->top = pnode; 
	}
	
} 
//返回棧頂元素
int  GetTop(Stack * ps){
	if(isEmpty(ps) == 0){
		return 	ps->top->data;
	}

} 
//元素出棧
void pop(Stack *ps){
	PNode p = ps->top;
	if(isEmpty(ps) == 0 && p !=NULL){
		ps->size--;
		ps->top = ps->top->next;
		free(p);
	}

} 
void ClearStack(Stack *ps){
	while(!isEmpty(ps)){
		pop(ps);
	}
} 
//銷燬一個棧
void DestryStack(Stack *ps){
	if(!isEmpty(ps))
		ClearStack(ps);
	free(ps);
		
}

//遍歷棧
void StackTraverse(Stack *ps){
	PNode p = ps->top;
	int num = ps->size;
	while(num--){
		printf("StackTraverse: %d\n",p->data);
		p = p->next;
	}
} 

int main(){
	Stack *ps = initStack(ps);
	int i;
	int num;
	for(i = 0;i<10;i++){
		push(ps,i);
		num = GetTop(ps);
		printf("GetTop(): %d\n",num);
	}
	
	for(i = 0;i<5;i++)
		pop(ps);
	StackTraverse(ps);
	DestryStack(ps);
	printf("isEmpty(): %d",isEmpty(ps));
	
	 return 0; 
} 

運行結果如下：