/in/foo.cc: In function 'int main()':
/in/foo.cc:13:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for(int j=head;j<=tail;j++)
   ^~~
/in/foo.cc:16:4: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
    if(f==false)
    ^~
/in/foo.cc:16:6: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
    if(f==false)
      ^