数据结构 -- 栈（一）

/******************************
* 
* 用数组表示栈
*
*******************************/


#include <stdio.h>

#define MAXSIZE 100

//元素elem 进栈
int push(char* a, int top, char elem)
{
    if(top >= (MAXSIZE-1))
    {
        printf("栈满");
        return -1;
    }
    a[++top] = elem;
    return top;
}

//数据元素出栈
int pop(char* a, int top)
{
    if(top == -1)
    {
        printf("空栈");
        return -1;
    }
    printf("出栈元素:%c 
",a[top]);
    top--;
    return top;
}

int main()
{
    char a[MAXSIZE];
    int top = -1;
    top = push(a, top, 'a');
    top = push(a, top, 'b');
    top = push(a, top, 'c');
    top = push(a, top, 'd');
    
    top = pop(a,top);
    top = pop(a,top);
    top = pop(a,top);
    top = pop(a,top);
    
    return 0;
}