/in/foo.cc: In function 'void qs(int, int)':
/in/foo.cc:12:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(i<r) qs(i,r);if(l<j) qs(l,j);
  ^~
/in/foo.cc:12:18: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  if(i<r) qs(i,r);if(l<j) qs(l,j);
                  ^~
/in/foo.cc: At global scope:
/in/foo.cc:15:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^