behavior： tight deadline, make a calculated risk
code: 先问 find most frequent item -> LC 散斯七 （不是爸） (k most frequent) -> follow up: what if the array was dynamic and changes every hour
behavior： tight deadline, make a calculated risk
code: 先问 find most frequent item -> LC 散斯七 （不是爸） (k most frequent) -> follow up: what if the array was dynamic and changes every hour