leetcode

0 // sort + count

1 class Solution {

2 public:

3 vector<int> smallerNumbersThanCurrent(const vector<int> &nums) const {

4 const int n = size(nums);

5 static int idxs[501];

6 vector<int> res(n);

7

8 iota(idxs, idxs + n, 0);

9 sort(idxs, idxs + n, [&](int a, int b) { return nums[a] < nums[b]; });

10

11 int cnt = 0;

12 for (int i = 1; i < n; i++) {

13 if (nums[idxs[i]] != nums[idxs[i - 1]]) {

14 cnt = i;

15 }

16 res[idxs[i]] = cnt;

17 }

18

19 return res;

20 }

21 };

22

23 // count

24 class Solution {

25 public:

26 vector<int> smallerNumbersThanCurrent(const vector<int> &nums) const {

27 const int n = size(nums);

28 static int count[101];

29 vector<int> res(n);

30

31 memset(count, 0x00, sizeof(count));

32 for (const int n : nums)

33 count[n + 1]++;

34 for (int i = 1; i <= 100; i++)

35 count[i] += count[i - 1];

36 for (int i = 0; i < size(nums); i++)

37 res[i] = count[nums[i]];

38

39 return res;

40 }

41 };