Add more problems to sieve of eratosthenes article

TrietMinh799 · TrietMinh799 · commit db1381b7c40b · 2023-08-23T21:59:19.000+07:00
diff --git a/src/algebra/primality_tests.md b/src/algebra/primality_tests.md
@@ -217,4 +217,4 @@ However, since these numbers (except 2) are not prime, you need to check additio
 
 ## Practice Problems
 
-- [SPOJ - Prime or Not](https://www.spoj.com/problems/PON/)
+- [SPOJ - Prime or Not](https://www.spoj.com/problems/PON/)
diff --git a/src/algebra/sieve-of-eratosthenes.md b/src/algebra/sieve-of-eratosthenes.md
@@ -254,6 +254,8 @@ However, this algorithm also has its own weaknesses.
 
 ## Practice Problems
 
+* [Leetcode - Four Divisors](https://leetcode.com/problems/four-divisors/)
+* [Leetcode - Count Primes](https://leetcode.com/problems/count-primes/)
 * [SPOJ - Printing Some Primes](http://www.spoj.com/problems/TDPRIMES/)
 * [SPOJ - A Conjecture of Paul Erdos](http://www.spoj.com/problems/HS08PAUL/)
 * [SPOJ - Primal Fear](http://www.spoj.com/problems/VECTAR8/)
