APL (Dyalog Unicode), 20 bytesSBCS Anonymous prefix lambda. {s=+/c←⍵?s←⍵*2:c⋄∇⍵} Try it online! {…} "dfn"; ⍵ is argument  ⍵*2 square the argument  s← assign to s (for square)  ⍵? find n random indices from 1…s without replacement  c← assign to c (for candidate)  +/ sum them  s= compa...