leetcode

0 class Solution {

1 public:

2 int totalHammingDistance(const vector<int> &nums) const {

3 const int n = size(nums);

4 int res = 0;

5

6 for (unsigned mask = 1; mask <= 1 << 30; mask <<= 1) {

7 int count =

8 accumulate(begin(nums), end(nums), 0, [&mask](int a, int b) { return a + !!(b & mask); });

9 res += count * (n - count);

10 }

11

12 return res;

13 }

14 };