leetcode-191 位1的个数

/**
 * @param {number} n
 * @return {number}
 */
var hammingWeight = function (n) {
  let result = 0;
  for (let i = 0; ; ++i) {
    const cur = BigInt(1) << BigInt(i);
    if (cur <= BigInt(n)) {
      if (BigInt(n) & cur) {
        result++;
      }
    } else {
      return result;
    }
  }
};
// hammingWeight(2147483645);