历届试题 正则问题

#include<iostream>
#include<cstdio>
#include<cstring>

using namespace std;

string s;

int pos = 0; 

int dfs()
{
	int tmp = 0, cnt = 0;
	
	while(s[pos]){
		if(s[pos] == '('){
			pos++;
			tmp += dfs();
		}
		else if(s[pos] == ')'){
			pos++;
			return max(tmp, cnt);
		}
		else if(s[pos] == '|'){
			pos++;
			
			cnt = max(tmp, cnt);
			tmp = 0;
		}
		else {
			pos++;
			tmp++;
		}
	}
	return max(tmp, cnt);	
} 
int main()
{
	cin >> s;
	
	cout << dfs() << endl;
	
	return 0;
}