B. Dreamoon and WiFi-Codeforces

B. Dreamoon and WiFi-Codeforces

// working.cpp by Bill Weinman <http://bw.org/>
#include <bits/stdc++.h>
using namespace std;
int main()
{
	string s1,s2;
	cin>>s1>>s2;
	int count=0,count1=0,count2=0,count3,count5,count6=0;
	for(int i=0;i<s1.size();i++)
	{
		if(s1[i]=='+')
			count1++;
		else
			count1--;
	}
	for(int i=0;i<s2.size();i++)
	{
		if(s2[i]=='?')
			count++;
		else if(s2[i]=='+')
			count2++;
		else
			count2--;
	}
	int x=pow(2,count);
	int y;
	for(int i=0;i<x;i++)
	{
		count3=0;
		if(i==0)
			count5=(count)*(-1);
		else
		{
			int l=i;
			while(l)
			{
				y=l%2;
				if(y==1)
					count3++;
				l/=2;
			}
		}
		count5=((count-count3)*(-1))+count3;
		if((count2+count5)==count1)
			count6++;
	}
	printf("%.12f",(float)count6/x);
	return 0;
}