D. J.:

- Added the leetcode problem and solution for 338

Author: nobodyPerfecZ

README.md

@@ -222,6 +222,7 @@
 - [309 Best Time to Buy and Sell Stock with Cooldown](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/description/)
 - [322 Coin Change](https://leetcode.com/problems/coin-change/description/)
 - [337 House Robber III](https://leetcode.com/problems/house-robber-iii/description/)
+- [338 Counting Bits](https://leetcode.com/problems/counting-bits/description/)
 - [354 Russian Doll Envelopes](https://leetcode.com/problems/russian-doll-envelopes/description/)
 - [373 Find K Pairs with Smallest Sums](https://leetcode.com/problems/find-k-pairs-with-smallest-sums/description/)
 - [377 Combination Sum IV](https://leetcode.com/problems/combination-sum-iv/description/)

awesome_python_leetcode/_338_counting_bits.py

@@ -0,0 +1,18 @@
+from typing import List
+
+
+class Solution:
+    """Base class for all LeetCode Problems."""
+
+    def countBits(self, n: int) -> List[int]:
+        """
+        Given an integer n, return an array ans of length n + 1 such that for each i
+        (0 <= i <= n), ans[i] is the number of 1's in the binary representation of i.
+        """
+        dp = [0 for _ in range(n + 1)]
+        if n >= 1:
+            dp[1] = 1
+        for i in range(2, n + 1):
+            offset = i & (1 << (i.bit_length() - 1)) - 1
+            dp[i] = 1 + dp[offset]
+        return dp

tests/test_338_counting_bits.py

@@ -0,0 +1,18 @@
+from typing import List
+
+import pytest
+
+from awesome_python_leetcode._338_counting_bits import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["n", "expected"],
+    argvalues=[
+        (2, [0, 1, 1]),
+        (5, [0, 1, 1, 2, 1, 2]),
+    ],
+)
+def test_func(n: int, expected: List[int]):
+    """Tests the solution of a LeetCode problem."""
+    bits = Solution().countBits(n)
+    assert bits == expected