Update README.md

Author: kamyu104

README.md

@@ -676,7 +676,7 @@
 0170| [Two Sum III - Data structure design](https://leetcode.com/problems/two-sum-iii-data-structure-design/) | [C++](./C++/two-sum-iii-data-structure-design.cpp) [Python](./Python/two-sum-iii-data-structure-design.py) | _O(n)_ | _O(n)_ | Easy | 🔒 |
 0187| [Repeated DNA Sequences](https://leetcode.com/problems/repeated-dna-sequences/) | [Python](./Python/repeated-dna-sequences.py) | _O(n)_       | _O(n)_          | Medium         ||
 0202| [Happy Number](https://leetcode.com/problems/happy-number/)      | [C++](./C++/happy-number.cpp) [Python](./Python/happy-number.py)   | _O(k)_  | _O(k)_          | Easy          ||
-0204| [Count Primes](https://leetcode.com/problems/count-primes/)  | [C++](./C++/count-primes.cpp) [Python](./Python/count-primes.py) | _O(nlog(logn))_        | _O(n)_          | Easy           ||
+0204| [Count Primes](https://leetcode.com/problems/count-primes/)  | [C++](./C++/count-primes.cpp) [Python](./Python/count-primes.py) | _O(nlog(logn))_        | _O(n)_          | Easy           || `Sieve of Eratosthenes`
 0205| [Isomorphic Strings](https://leetcode.com/problems/isomorphic-strings/) | [C++](./C++/isomorphic-strings.cpp) [Python](./Python/isomorphic-strings.py) | _O(n)_ | _O(1)_       | Easy           || 
 0217| [Contains Duplicate](https://leetcode.com/problems/contains-duplicate/)  | [C++](./C++/contains-duplicate.cpp) [Python](./Python/contains-duplicate.py) | _O(n)_        | _O(n)_          | Easy           ||
 0219| [Contains Duplicate II](https://leetcode.com/problems/contains-duplicate-ii/)  | [C++](./C++/contains-duplicate-ii.cpp) [Python](./Python/contains-duplicate-ii.py) | _O(n)_        | _O(n)_          | Easy           ||
@@ -858,7 +858,7 @@
 1150| [Check If a Number Is Majority Element in a Sorted Array](https://leetcode.com/problems/check-if-a-number-is-majority-element-in-a-sorted-array/) | [C++](./C++/check-if-a-number-is-majority-element-in-a-sorted-array.cpp) [Python](./Python/check-if-a-number-is-majority-element-in-a-sorted-array.py) | _O(nlogn)_ | _O(1)_ |  Easy |🔒| Binary Search
 1157| [Online Majority Element In Subarray](https://leetcode.com/problems/online-majority-element-in-subarray/) | [C++](./C++/online-majority-element-in-subarray.cpp) [Python](./Python/online-majority-element-in-subarray.py) | ctor: _O(n)_<br>query: _O(klogn)_ | _O(n)_ |  Hard || Binary Search, Segment Tree, `Boyer–Moore Majority Vote Algorithm`
 1154| [Day of the Year](https://leetcode.com/problems/day-of-the-year/) | [C++](./C++/day-of-the-year.cpp) [Python](./Python/day-of-the-year.py) | _O(1)_ | _O(1)_ |  Easy ||
-1175| [Prime Arrangements](https://leetcode.com/problems/prime-arrangements/) | [C++](./C++/prime-arrangements.cpp) [Python](./Python/prime-arrangements.py) | _O(n)_ | _O(n)_ |  Easy ||
+1175| [Prime Arrangements](https://leetcode.com/problems/prime-arrangements/) | [C++](./C++/prime-arrangements.cpp) [Python](./Python/prime-arrangements.py) | _O(nlog(logn))_ | _O(n)_ |  Easy || `Sieve of Eratosthenes`
 1185| [Day of the Week](https://leetcode.com/problems/day-of-the-week/) | [C++](./C++/day-of-the-week.cpp) [Python](./Python/day-of-the-week.py) | _O(1)_ | _O(1)_ |  Easy || `Zeller Formula`
 1197 | [Minimum Knight Moves](https://leetcode.com/problems/minimum-knight-moves/) | [C++](./C++/minimum-knight-moves.cpp) [Python](./Python/minimum-knight-moves.py) | _O(1)_ | _O(1)_ | Medium |🔒| DP, Math |
 1217 | [Play with Chips](https://leetcode.com/problems/play-with-chips/) | [C++](./C++/play-with-chips.cpp) [Python](./Python/play-with-chips.py) | _O(n)_ | _O(1)_ | Medium |||