numberof1Bits.js

////////////////////////////////////////////////Number of 1 Bits/////////////////////////////////////////////
// Write a function that takes an unsigned integer and returns the number of '1' bits it has (also known as the Hamming weight).
// Note:
// Note that in some languages, such as Java, there is no unsigned integer type. In this case, the input will be given as a
// signed integer type. It should not affect your implementation, as the integer's internal binary representation is the same, whether it is signed or unsigned.
// In Java, the compiler represents the signed integers using 2's complement notation. Therefore, in Example 3, the input represents the signed integer. -3.
// Example 1:
// Input: n = 00000000000000000000000000001011
// Output: 3
// Explanation: The input binary string 00000000000000000000000000001011 has a total of three '1' bits.
// Example 2:
// Input: n = 00000000000000000000000010000000
// Output: 1
// Explanation: The input binary string 00000000000000000000000010000000 has a total of one '1' bit.
// Example 3:
// Input: n = 11111111111111111111111111111101
// Output: 31
// Explanation: The input binary string 11111111111111111111111111111101 has a total of thirty one '1' bits.
// Constraints:
// The input must be a binary string of length 32.
// Follow up: If this function is called many times, how would you optimize it?
/**
 * @param {number} n - a positive integer
 * @return {number}
 */
 const hammingWeight = function(n) {
    let sum = 0;
    while (n !== 0) {
        sum++;
        n &= n - 1;
    }
    return sum;
};

// console.log(hammingWeight(00000000000000000000000000001011));
// console.log(hammingWeight(00000000000000000000000010000000));
// console.log(hammingWeight(11111111111111111111111111111101));