#+title: C++ Tricks

* Rotate String Check :string:trick:search:
:PROPERTIES:
:ANKI_NOTE_TYPE: Basic
:ANKI_NOTE_ID: 20260504001
:END:
** Front
How to check if string ~s~ can be rotated to match string ~goal~ in O(n)?
** Back
#+begin_src c++
bool rotateString(string s, string goal) {
    return s.size() == goal.size() && (s + s).find(goal) != string::npos;
}
#+end_src

If ~goal~ is a substring of ~s + s~, then ~s~ can be rotated to match ~goal~.