学步园

#include "./stack/stack.h"
#include<stdlib.h>
SElemType Precede(SElemType t1, SElemType t2)
{
	SElemType f;
	switch(t2)
	{
	case '+':
	case '-':
		if(t1 == '(' || t1 == '=')
			f = '<';
		else
			f = '>';
		break;
	case '*':
	case '/':
		if(t1 == '*' || t1 == '/' || t1 == ')')
			f = '>';
		else
			f = '<';
		break;
	case '(':
		if(t1 == ')')
		{
			printf("ERROR\n");
			exit(ERROR);
		}
		else
		{
			f = '<';
		}
		break;
	case ')':
		switch(t1)
		{
		case '(': f='=';
			break;
		case '=':printf("ERROR\n");
			exit(ERROR);
		default:
			f = '>';
		}
		break;
	case '=':
			switch(t1)
			{
			case '=': f='=';
				break;
			case '(':
				printf("ERROR\n");
				exit(ERROR);
			default:
				f = '>';
			}
			
	}
	return f;
}

Status In(SElemType c)
{
	switch (c)
	{
	case '+':
	case '-':
	case '*':
	case '/':
	case '(':
	case ')':
	case '=':
		return TRUE;
	default:
		return FALSE;
	}
}

SElemType Operate(SElemType a, SElemType theta, SElemType b)
{
	SElemType c;
	switch (theta)
	{
	case '+': 
		c = a + b;
		break;
	case '-':
		c = a - b;
		break;
	case '*':
		c = a * b;
		break;
	case '/':
		c = a / b;
		break;
	}
	return c;
}

SElemType EvalueteExpresion()
{
	SqStack OPTR,OPND;
	SElemType a, b, d, x, theta;
	char c;
	char z[6];
	int i;
	InitStack(OPTR);
	Push(OPTR, '=');
	InitStack(OPND);
	c = getchar();
	GetTop(OPTR, x);
	while(c != '=' || x != '=')
	{
		if(In(c))
		{
			switch (Precede(x, c))
			{
			case '<': Push(OPTR,c);
				c = getchar();
				break;
			case '=': Pop(OPTR,x);
				c = getchar();
				break;
			case '>':
				Pop(OPTR, theta);
				Pop(OPND, b);
				Pop(OPND, a);
				Push(OPND, Operate(a, theta, b));
				break;
			}
		}
		else if(c >= '0' && c <= '9')
		{
			i = 0;
			do{
				z[i++] = c;
				c = getchar();
			}while(c >= '0' && c <= '9');
			z[i] = '\0';
			d = atoi(z);
			Push(OPND, d);
		}
		else
		{
			printf("ERROR\n");
			exit(ERROR);
		}
		GetTop(OPTR, x);
	}
	GetTop(OPND, x);
	return x;
}

int main()
{
	printf("请输入算术表达式,负数要（0-正数），并以=结束\n");
	printf("%d\n",EvalueteExpresion());
	return 0;
}

输入四则运算表达式字符串，计算该表达式的值（计算中间结果和最后结果范围为int类型）