[Easy] 191. Number of 1Bits (Java)

https://leetcode.com/problems/number-of-1-bits/

Number of 1 Bits - LeetCode

음주 이슈,,,

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※  Question Summary

▶ Given an unsigned integer and return the number of '1' bits it has (known as the Hamming weight)

▶ Use integer as unsigned integer since there is no unsigned integer in Java

▶ Input : Unsigned integer n

▶ Output : Return the number of '1'bits it has

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◈ Constraints

• The input must be a binary string of length 32.

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◈ Input - 1

00000000000000000000000000001011

◈ Output - 1

3

◈ Input - 2

00000000000000000000000010000000

◈ Output - 2

1

◈ Input - 3

11111111111111111111111111111101

◈ Output - 3

31

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 ◎  HOW TO SOLVE IT

▶ An unsigned integer has 4 bytes, which means it needs to be checked for 32 bits

▶ Check 'n & 1' 32 times, and each time after checking, shift 'n' to the right by 1 bit

▶ return the count of 1bits

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public class Solution {
    // you need to treat n as an unsigned value
    public int hammingWeight(int n) {
        int nCount = 0;
        for(int i = 0; i < 32; i++) {
            int nBit = n & 1;
            if(nBit == 1)
                nCount++;
            n = n >> 1;
        }
        return nCount;
    }
}

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I HOPE YOUR DAY GOES WELL :)