Number of 1 Bits 15 XP Easy

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Count the number of '1' bits in an integer (Hamming weight).

# Method 1: n & 1 to check last bit, then n >>= 1
# Method 2: n & (n-1) removes lowest set bit — count iterations

# n=11 → 1011 → three 1-bits

The n &= (n-1) trick is elegant: it removes one set bit per iteration, so we loop exactly count times.

💡 Pro tip: Understand this problem deeply — don't just memorize the code. Try explaining the approach out loud as if teaching a friend. If you can explain it simply, you truly understand it!

📋 Instructions

Count 1-bits for n=11 and n=128.

While n > 0: n &= (n-1), count += 1. The loop runs exactly 'number of 1-bits' times.

🧪 Test Cases

Input

hammingWeight(11)

Expected

3

Test case 1

Input

hammingWeight(128)

Expected

1

Test case 2

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main.py

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Output

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