class Solution {public:    string addBinary(string a, string b) {       string::reverse_iterator itea,iteb;	   string result;	   char temp;	   int flag =0;	   for(itea = a.rbegin(), iteb = b.rbegin(); itea != a.rend()&& iteb !=b.rend(); itea++, iteb++ )	   {         temp = GetResult(*itea,*iteb,flag);		 if(temp >= 2)		 {           flag =1;		   temp = temp%2;		 }		 else		 {          	flag =0;		 }		 result.insert(result.begin(),temp + ‘0‘);	    }	   for(; itea != a.rend(); itea++)      	{      	   temp = GetResult(*itea,‘0‘,flag);      	   if(temp >= 2)      	   {      		 flag =1;      		 temp = temp%2;      	   }      	   else      	   {      		  flag =0;      	   }      	   result.insert(result.begin(),temp + ‘0‘);      	}	   for(; iteb != b.rend(); iteb++)	   {			 temp = GetResult(*iteb,‘0‘,flag);			 if(temp >= 2)			 {			   flag =1;			   temp = temp%2;			 }			 else			 {				flag =0;			 }			result.insert(result.begin(),temp + ‘0‘);	   }	   if(flag != 0)	   result.insert(result.begin(),‘1‘);	   return result;            }	char GetResult(char a, char b,int flag)	{	   char result;	   a = a -‘0‘;	   b = b - ‘0‘;	   result = a + b + flag;	   return result;	}};