算法学习 - 栈的链表实现（C++）

//
//  main.cpp
//  Stack
//
//  Created by Alps on 14-7-27.
//  Copyright (c) 2014年 chen. All rights reserved.
//

#include <iostream>

using namespace std;

struct Node;
typedef Node * PtrToNode;
typedef PtrToNode Stack;

struct Node{
int X;
PtrToNode Next;
};

int isEmpty(Stack S){
return S->Next == NULL;
}

Stack createStack(void){
Stack S;
S = (Stack)malloc(sizeof(Node));
S->Next = NULL;
return S;
}

void Push(Stack S, int X){
Stack element;
element = (Stack)malloc(sizeof(Node));
element->X = X;
element->Next = S->Next;
S->Next = element;
}

void Pop(Stack S){
if (!isEmpty(S)) {
Stack tmp = S->Next;
S->Next = tmp->Next;
free(tmp);
}else{
printf("Empty stack can't pop cell\n");
}
}

int Top(Stack S){
int X;
if (!isEmpty(S)) {
return X = S->Next->X;
}else{
printf("empty stack, no top cell\n");
}
return 0;
}

void makeEmpty(Stack S){
if (S == NULL) {
printf("create stack first\n");
}
while (!isEmpty(S)) {
Pop(S);
}
}

int main(int argc, const char * argv[])
{
Stack S = createStack();
Push(S, 2);
Push(S, 4);
Push(S, 6);
Push(S, 8);
printf("%d\n",Top(S));
Pop(S);
printf("%d\n",Top(S));
makeEmpty(S);
printf("%d\n",Top(S));
return 0;
}