leetcode

0 #define LOG2(X) ((unsigned)(8 * sizeof(int) - __builtin_clz((X)) - 1))

1

2 class Solution {

3 int flip(int label) {

4 int log = LOG2(label), floor = 1 << log, ceil = (1 << log + 1) - 1;

5 return floor + ceil - label;

6 }

7

8 public:

9 vector<int> pathInZigZagTree(int label) {

10 bool rev = LOG2(label) % 2;

11 vector<int> res({label});

12 if (rev) label = flip(label);

13 while ((label /= 2) > 0) {

14 rev = !rev;

15 res.push_back(!rev ? label : flip(label));

16 }

17 reverse(res.begin(), res.end());

18 return res;

19 }

20 };