数据结构—栈练习

// 栈操作练习 

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

#define OK 1
#define ERROR 0 
#define STACK_INIT_SIZE 20
#define STACK_INCERT	10 

typedef char ElemType;
typedef int Status;

typedef struct{
	ElemType *base;		//栈底指针：存储空间基址 
	ElemType *top;		//栈顶指针 指向栈顶元素的下一个地址
	int stacksize;		//允许最大容量 
} SqStack; 

Status InitStack (SqStack &S);			//构造空栈 
Status StackTraverse (SqStack S);		//遍历栈 
Status Push (SqStack &S,ElemType e);	//插入e为新的栈顶元素 
Status Pop (SqStack &S,ElemType &e);	//删除栈顶元素并用e返回 
Status GetTop (SqStack S,ElemType &e);	//用e返回栈顶元素 


//TEST

int main(){
	SqStack S;
	InitStack(S);
	
	Push(S,'A');
	Push(S,'B');
	StackTraverse(S);
	
	ElemType e;
	GetTop(S,e);
	printf("%c\n",e);
	
	Pop(S,e);
	printf("%c\n",e);
	StackTraverse(S);
	
}



Status InitStack (SqStack &S){
	S.base = (ElemType*)malloc(sizeof(ElemType)*STACK_INIT_SIZE);
	if(!S.base) return ERROR;
	S.stacksize = STACK_INIT_SIZE;
	S.top=S.base;
	return OK;
}

Status GetTop (SqStack S,ElemType &e){
	if(S.base==S.top) return ERROR;		//判断空栈 
	e = *(S.top-1);
	return OK;
}

Status Push (SqStack &S,ElemType e){
	if(S.top-S.base>=STACK_INIT_SIZE) {
		S.base = (ElemType*)realloc(S.base,(S.stacksize+STACK_INCERT)*sizeof(ElemType));
		if(!S.base) return ERROR;
		S.top=S.base+S.stacksize;
		S.stacksize+=STACK_INCERT;
	}		//栈满 
	*(S.top) = e;
	S.top++;
	return OK;
}

Status Pop (SqStack &S,ElemType &e){
	if(S.base==S.top) return ERROR;
	S.top--;
	e=*(S.top);
	return OK;
}

Status StackTraverse (SqStack S){
	if (S.base==S.top ) return ERROR; 
	ElemType *temp=S.top;
	while(temp-S.base>0){
		temp--;
		printf("%c ",*(temp));
	}
	printf("\n");
}