leetcode

0 class Solution {

1 static inline constexpr const array<int, 1001> dp = []() constexpr -> array<int, 1001> {

2 array<int, 1001> dp;

3 dp[0] = 0;

4 for (int i = 1; i <= 1000; i++) {

5 int res = 0, n = i;

6 while (n != 1) {

7 n = (n % 2) ? 3 * n + 1 : n / 2;

8 res++;

9 }

10 dp[i] = res;

11 }

12 return dp;

13 }();

14

15 public:

16 int getKth(int lo, int hi, int k) {

17 vector<int> vec(hi - lo + 1);

18

19 iota(begin(vec), end(vec), lo);

20 nth_element(begin(vec), begin(vec) + k - 1, end(vec),

21 [](const int a, const int b) { return dp[a] == dp[b] ? a < b : dp[a] < dp[b]; });

22

23 return vec[k - 1];

24 }

25 };