Euler totient
Compute Euler's totient phi(n): the count of integers in [1, n] that are coprime to n. For example phi(9) = 6 (1,2,4,5,7,8). Constraints: 1 <= n <= 1e12, with phi(1) = 1 by convention. Use the product formula over distinct prime factors; do not loop over all integers up to n.
Implement
euler_totient(n: int) → intExamples
in
[9]out6What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
0:00 of about 25 min
solution.py
InputExpectedGot
[9]6not run yetsample