countDownLatch.countDown() should be inside execute function

like follows: for(int i= 0; i < total; i++){ executor3.execute(() -> { cw.addWord("word3"); countDownLatch.countDown(); }); }

https://github.com/mission-peace/interview/blob/94be5deb0c0df30ade2a569cf3056b7cc1e012f4/src/com/interview/multithreaded/CountingWord.java#L72