leetcode

0 class Solution {

1 public:

2 int countTriplets(const vector<int> &arr) {

3 static int left[301];

4 left[0] = 0;

5 int n = arr.size(), res = 0;

6

7 for (int i = 0, acc = 0; i < n; i++)

8 left[i + 1] = acc ^= arr[i];

9

10 for (int i = 0; i < n; i++) {

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

12 if (left[i] == left[j + 1]) res += j - i;

13 }

14 }

15

16 return res;

17 }

18 };