Prime count up to n
Return the number of prime numbers less than or equal to n (the prime-counting function pi(n)), for n up to 10^6. Per-number trial division is too slow; build a Sieve of Eratosthenes once and count the survivors. Return 0 for n < 2.
Implement
count_primes(n: int) → intExamples
in
[10]out4What 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 20 min
solution.py
InputExpectedGot
[10]4not run yetsample