#include <stdio.h>
#include "stack-c.h"

int getop(struct Stack* pS, int* n1, int* n2)
{
	if( pS->empty() )
	{
		printf("empty stack!\n");
		return 0;
	}
	*n2 = pS->pop();

	if( pS->empty() )
	{
		pS->push(*n2);
		printf("two operands needed!\n");
		return 0;
	}
	*n1 = pS->pop();
	return 1;
}

int main(void)
{
	struct Stack* pS = createStack();
	while (1)
	{
		char str[31];
		int i;
		printf("> ");
		gets_s(str, sizeof(str));
		if( sscanf_s(str, " %d", &i, sizeof(i))==1 ) pS->push(i);
		else
		{
			int n1, n2;
			char c;
			sscanf_s(str, "%c", &c, sizeof(char));
			switch(c)
			{
				case '+':
					if (getop(pS, &n1, &n2)) pS->push(n1+n2);
					break;
				case '-':
					if (getop(pS, &n1, &n2)) pS->push(n1-n2);
					break;
				case '/':
					if (getop(pS, &n1, &n2))
					{
						if( n2 != 0 )
							pS->push(n1/n2);
						else
						  printf(" nao divide por zero \n");
					}
					break;
				case '*':
					if (getop(pS, &n1, &n2)) pS->push(n1*n2);
					break;
				case 'q':
					return 0;
				default:
					printf("error\n");
			}
		}
		pS->listaElems();
	}
}