number of 1 bits solution

Author: jylee2033

number-of-1-bits/jylee2033.py

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+class Solution:
+    def hammingWeight(self, n: int) -> int:
+        # 1. Find highest power of 2 range that covers n
+        # 2. Greedily subtract from largest power of 2 to smallest
+
+        # powers : 1 + 2 + 4 +  8 + 16 + ...
+        # total  : 1 + 3 + 7 + 15 + 31 + ...
+        # index  : 0   1   2    3    4
+
+        i = 0
+        total = 1
+
+        while n > total:
+            i += 1
+            total += 2 ** i
+
+        count = 0
+
+        for j in range(i, -1, -1):
+            if n >= 2 ** j:
+                n -= 2 ** j
+                count += 1
+
+        return count
+
+# Time Complexity : O(log n)
+# Space Complexity : O(1)