Count Primes
Given an integer n, return the number of prime numbers that are strictly less than n.
Example 1
Input
n = 10Output
4There are 4 prime numbers less than 10: 2, 3, 5, and 7.
Example 2
Input
n = 0Output
0There are no prime numbers strictly less than 0.
Constraints
- 0 <= n <= 5 * 10^6