二进制中1的个数

Question

直接转换

function toBinary(num) {
  let str = "";
  while (num) {
    str = (num % 2) + str;
    num = Math.floor(num / 2);
  }
  return str;
}

function getBinaryOneCounts(num) {
  const binStr = toBinary(num);
  let count = 0;
  for (let i = 0; i < binStr.length; i++) {
    if (binStr[i] == '1') {
      count++;
    }
  }
  return count;
}

console.log(getBinaryOneCounts(10))

与操作

function hammingWeight(n) {
  let count = 0;
  while (n !== 0) {
    if ((n & 1) === 1) {
      count++;
    }
    n = n >>> 1;
  }
  return count;
};

总结

第一种方法不支持负数