func_code_string: #include <bits/stdc++.h>   typedef long long int ll;   typedef unsigned long long int ull;   #define N 1010100   #define inf 1e9      #define loop(x, n, r) for(int i = x; i < n; i += r)      #define pb push_back   #define pp pair<int, int>      using namespace std;      int main(){       ios::sync_with_stdio(0); cin.tie(0);       int T = 1;       cin >> T;       while(T--){           int n;           cin >> n;           string b;           cin >> b;           cout <<  1 ;           char prev = b[0] ==  0  ?  1  :  2 ;           loop(1, n, 1){               if(prev ==  2 ){                   if(b[i] ==  1 )                       cout <<  0 ;                   else                       cout <<  1 ;                   prev =  1 ;               }               else if(prev ==  1 ){                   if(b[i] ==  1 ){                       cout <<  1 ;                       prev =  2 ;                   }                   else{                       cout <<  0 ;                       prev =  0 ;                   }               }               else{                   if(b[i] ==  1 ){                       cout <<  1 ;                       prev =  2 ;                   }                   else{                       cout <<  1 ;                       prev =  1 ;                   }               }           }           cout <<   n ;       }       return 0;   }   