UVA 12545(p253)----Bits Equalizer

#include<iostream>#include<cstdio>#include<algorithm>using namespace std;int t,l,zero,one,temp1,temp2,qnum;string st1,st2;int main(){    ios::sync_with_stdio(false);    cin>>t;    int cas=0;    while(t--)    {        cin>>st1>>st2;        cas++;zero=0;one=0;        qnum=0;temp1=0;temp2=0;        l=st1.length();        for(int i=0;i<l;i++)        {            if(st1[i]=='?')            {                if(st2[i]=='0') zero++;                if(st2[i]=='1') one++;                qnum++;            }            if(st1[i]=='0'&&st2[i]=='1') temp1++;            if(st1[i]=='1'&&st2[i]=='0') temp2++;        }        if(one+temp1<temp2) cout<<"Case "<<cas<<": "<<-1<<endl;        else          if(temp1>=temp2) cout<<"Case "<<cas<<": "<<temp1+qnum<<endl;            else cout<<"Case "<<cas<<": "<<temp2+qnum<<endl;    }    return 0;}