给定一个中缀表达式转成后缀表达式

#include<bits/stdc++.h>
using namespace std;

string s;
stack<char> q;

int judge(char ch)
{
	if(ch == '(') return 6;
	if(ch == '*' || ch == '/') return 3;
	if(ch == '+' || ch == '-') return 1;
	if(ch == ')') return 0;
}

int main()
{
	cin >> s;
	for(int i = 0;i < s.size();i++)
	{
		if(s[i] >= 'A' && s[i] <= 'Z')//遇见字符直接输出 
		{
			cout<<s[i];
		}
		else//如果是运算符 
		{
			if(q.empty() || judge(s[i]) > judge(q.top())) q.push(s[i]);//如果栈为空或该字符的优先级大于栈顶的优先级,直接入栈 
			else while(judge(s[i]) <= judge(q.top()))
			    {
			    	if(s[i] == ')' && q.top() == '(') q.pop();
				    else {
				        cout<<q.top();
				        q.pop();
				        q.push(s[i]);
					}
			    }
		}
	}
	return 0;	
}

真的不知道哪里错了...