Sync LeetCode submission Runtime - 68 ms (44.32%), Memory - 23.1 MB (65.19%)

Author: jimit105

0338-counting-bits/solution.py

@@ -1,13 +1,12 @@
-# Approach 4 - DP + Last Set Bit
+# Approach 3: DP + Least Significant Bit
 
-# Time: O(N)
+# Time: O(n)
+# Space: O(1)
 
 class Solution:
     def countBits(self, n: int) -> List[int]:
         ans = [0] * (n + 1)
-        
         for x in range(1, n + 1):
-            ans[x] = ans[x & (x - 1)] + 1
-            
-        return ans
-        
+            ans[x] = ans[x >> 1] + (x & 1)
+
+        return ans