A Random Question from a Competition

#1

Problem Statement
We have
N
integers
A
1
,
A
2
,
.
.
.
,
A
N
.

There are
N
(
N
−
1
)
2
ways to choose two of them and form a pair. If we compute the product of each of those pairs and sort the results in ascending order, what will be the
K
-th number in that list?

Constraints
All values in input are integers.

2<=N<=2x10^5

1<=k<=N(N-1)/2

-10^9 <=Ai<=10^9

can you help me in writing an optimized code.

#2

30 413 -170202098 -268409015 537203564 983211703 21608710 -443999067 -937727165 -97596546 -372334013 398994917 -972141167 798607104 -949068442 -959948616 37909651 0 886627544 -20098238 0 -948955241 0 -214720580 277222296 -18897162 834475626 0 -425610555 110117526 663621752 0

#3

output: 448283280358331064

#4

Sort the values and then use two pointer approach.

#5

You can even do lower_bound for each no to find the other pair in the array

#6

@dare_devil_007 If you feel your doubt has been resolved you can mark this doubt as resolved.

#7

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#8

yeah but can you please explain it with a code which i think is a better way to me to understand.

#9

@dare_devil_007 We can help you with the logic and understanding. It is your homework to do the coding work.