Top K # https://www.evernote.com/shard/s440/client/snv?noteGuid=db5d1f47-fc86-4bed-3323-46a19a029216¬eKey=53aa5fffcc236d3b7ef209ef5d916639&sn=https%3A%2F%2Fwww.evernote.com%2Fshard%2Fs440%2Fsh%2Fdb5d1f47-fc86-4bed-3323-46a19a029216%2F53aa5fffcc236d3b7ef209ef5d916639&title=Design%2Ba%2Bsystems%2Bwhich%2Bfinds%2BTop%2BK%2528Heavy%2BHitters%2529