/in/foo.cc: In function 'int main()':
/in/foo.cc:81:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
     if(!dfn[i]) 
     ^~
/in/foo.cc:83:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
  for (int i=1;i<=N;i++)
  ^~~