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