/in/foo.cc: In function 'int main()':
/in/foo.cc:11:15: error: 'b' was not declared in this scope
   11 |         while(b[0]!=0){
      |               ^
/in/foo.cc:21:25: error: 'i' was not declared in this scope
   21 |                 while(b[i]==1)i--;
      |                         ^
/in/foo.cc:22:19: error: 'i' was not declared in this scope
   22 |                 b[i]++;
      |                   ^
/in/foo.cc:20:21: warning: unused variable 'j' [-Wunused-variable]
   20 |                 int j=n;
      |                     ^