leetcode

0 class Solution {

1 static const int MOD = 1E9 + 7;

2

3 public:

4 int concatenatedBinary(int n) const {

5 long crnt = 0;

6 for (int i = 1, size = 0; i <= n; i++) {

7 if (__builtin_popcount(i) == 1) size++;

8 crnt = ((crnt << size) + i) % MOD;

9 }

10 return crnt;

11 }

12 };