表达式求值和括号匹配（栈的应用）

//括号的匹配
int matching()
{
	Stack s;
	InitStack(s);
	int flag = 1;
	char ch[10] = "[(]]#";
	//读入
	//cin >> ch;
	int i = 0;
	while (ch[i] != '#' && flag != 0)//假设字符串以#结尾
	{
		if (ch [i] == '(' || ch[i] == '[')
		{
			PushbackStack(s, ch[i]);//入栈 
		}
		if (ch[i] == ')' || ch[i] == ']')
		{
			if (IsEmpty(s))
			{
				flag = 0;
				break;
			}
			//判断是否匹配并将栈顶元素出栈
			ElemType tmp = StackTop(s);
			flag = ISMatch(tmp, ch[i]);
		}
		i++;
		//读入下一个字符
		//cin >> ch;
	}
	//如果栈空且flag=1,则匹配成功
	if (IsEmpty(s) && flag == 1)
		return OK;
	return ERROR;
}
int ISMatch(char tmp,char ch)
{
	if ((tmp == '(' && ch == ')') || (tmp == '[' && ch == ']'))
		return OK;
	else
		return ERROR;
}

//优先级比较>——1，';
	else if (flag == 0)
		return '=';
	else if (flag == -1)
		return '> ch;
	PushbackStack(OPTR, ch);
	cin >> ch;
	while (ch!='#'||Stac服务器托管网kTop(OPTR)!='#')
	{
		if (isdigit(ch))
		{
			PushbackStack(OPND, ch-48);//将字符转为数字，如果是ch,结果为-1
			cin >> ch;
		}
		else
		{
			//PushbackStack(OPTR, ch);
			//获取栈顶元素并比较
			char c1 = StackTop(OPTR);
			char c = PriorityComparison(c1, ch);
			switch (c)
			{
			case'>':
				//弹出两个数字
				//int b = Popback(OPND);
				//int a = Popback(OPND);
				c1=Popback(OPTR);//符号出栈
				PushbackStack(OPND, calculating(Popback(OPND),
					c1, Popback(OPND)));//计算结果并入栈
				break;
			case'> ch;
			服务器托管网	break;
			case'=':
				//弹出栈顶的‘（’
				Popback(OPTR);
				cin >> ch;
				break;
			}

		}
	}

	return (int)StackTop(OPND);
}