Problem
A prime is an integer greater than 1 divisible only by 1 and itself. Add every prime strictly smaller than limit. The limit itself is excluded even when it is prime.
Implement prime_sum(limit).
Input
limit: The exclusive upper bound.
Output
Return the sum of the eligible primes, or 0 when none exist.
Constraints
0 ≤ limit ≤ 2,000,000. Return the sum using a signed 64-bit integer.
Examples
Example 1
Input:
limit = 12
Expected output:
expected = 28Input:
long long limit = 12;
Expected output:
long long expected = 28;Input:
long limit = 12;
Expected output:
long expected = 28;Explanation
The primes below 12 are 2, 3, 5, 7, and 11; their sum is 28.
Example 2
Input:
limit = 2
Expected output:
expected = 0Input:
long long limit = 2;
Expected output:
long long expected = 0;Input:
long limit = 2;
Expected output:
long expected = 0;Explanation
There are no primes strictly below 2.
References
This challenge is adapted for CodeUtility. Follow the statement and constraints above.