data structures - Finding K smallest values in an array (Heap vs QuickSelect) -

let's assume have array , wish find k smallest values of :

there 2 approaches :

1.using quick select algorithm (o(n) time complexity , o(1) space)

2.using min heap data structure (o(nlogk) time complexity , o(k) space)

i'd know when 1 preferred on one.

i guess both of them can distributed.

check out:-

quick select sorting or heap

as sorting whole dataset quite slow, makes sense select top k items , sort few ‘top’ elements giving impression user whole dataset sorted pages through result set. give running time of o(k*log(k) + n) opposed o(n*log(n)) faster if k reasonably small (few hundreds example).

an other approach work heap , keep popping smallest number while putting larger receiving n numbers stream. work o(n*log(k)) running time heap holds k elements height log(k) while test n numbers in total, although it’s expected running time larger quick select , sort combination.