/in/foo.cc: In function 'int main()':
/in/foo.cc:20:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(int i = 1; i <= n; i++) 
  ^~~
/in/foo.cc:22:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   for(int j = 1; j <= k / 2; j++) 
   ^~~
/in/foo.cc:23:14: error: 'i' was not declared in this scope
    fa[father(i + j - 1)] = father(i + k - j);
              ^