infix to postfix 完整版

#include<iostream>
#include<stack>
#include<string>
#include<deque>
using namespace std;
 
char compare(char tp, char op)
{
	if (((tp == '+' || tp == '-') && (op == '*' || op == '/')) || (tp == '#'))
		return '<';
	else if (tp == '('&&op != ')')
		return '<';
	else if ((tp == '*' || tp == '/' || tp == '+' || tp == '-') && (op == '('))
		return '<';
	return '>';
}
 
int main()
{
	stack<char>num;
	stack<char>oper;
 
	oper.push('#');
 
	string s;
	cin >> s;
 
	for (int i = 0; i<s.length(); i++)
	{
		if (s[i] == '0' || s[i] == '1' || s[i] == '2' || s[i] == '3' || s[i] == '4' || s[i] == '5' || s[i] == '6' || s[i] == '7' || s[i] == '8' || s[i] == '9')
			num.push(s[i]);
		else
		{
			char comp = compare(oper.top(), s[i]);
			if (comp == '<')
				oper.push(s[i]);
			else if (comp == '>')
			{
				if (s[i] == ')')
				{
					while (oper.top() != '(')
					{
						num.push(oper.top());
						oper.pop();
					}
					oper.pop();
				}
				else
				{
					num.push(oper.top());
					oper.pop();
					oper.push(s[i]);
				}
			}
		}
	}
 
	while (oper.top() != '#')
	{
		num.push(oper.top());
		oper.pop();
	}
 
	deque<char> d;
 
	while (num.size() != 0)
	{
		d.push_front(num.top());
		num.pop();
	}
 
	for (auto i = d.begin(); i != d.end(); i++)
		cout << *i;
 
	cout << endl;
 
	return 0;
}