ZOJ 4033 CONTINUE...?（The 15th Zhejiang Provincial Collegiate Programming Contest Sponsored by TuSimple）

 #include <iostream>
 #include <algorithm>
 using namespace std;
 
 const int maxn = 1e5 + ;
 int a[maxn];
 
 int main(){
     int t;
     cin >> t;
     while(t--){
         int n;
         cin >> n;
         string s;
         cin >> s;
         int sum = ;
         bool l = true;
         int i;
         for(i = n-;i >= ;i -= ){
             sum += *i+;
             if(l){
                 if(s[i] == ''){
                     a[i] = ;
                 }
                 else
                     a[i] = ;
                 if(s[i-] == ''){
                     a[i-] = ;
                 }
                 else a[i-] = ;
                 l = false;
             }
             else{
                 if(s[i] == ''){
                     a[i] = ;
                 }
                 else
                     a[i] = ;
                 if(s[i-] == ''){
                     a[i-] = ;
                 }
                 else a[i-] = ;
                 l = true;
             }
         }
         if(i == ){
             sum += ;
             if(l){
                 if(s[] == ''){
                     a[] = ;
                 }
                 else
                     a[] = ;
             }
             else{
                 if(s[] == ''){
                     a[] = ;
                 }
                 else
                     a[] = ;
             }
         }
 
         if(sum%){
             cout << - << endl;
             continue;
         }
         else{
             for(int j = ;j < n;j++){
                 cout << a[j] ;
             }
             cout << endl;
         }
 
     }
     return ;
 }