To solve this problem, we need to find the number of triplets (i, j, k) such that the XOR of the subarray from i to j-1 is equal to the XOR of the subarray from j to k. This can be achieved using the properties of the XOR operation.
- Prefix XOR: Compute the prefix XOR for each position in the array. The prefix XOR up to index
i
is the XOR of all elements from the start of the array to indexi
. - Utilize Prefix XOR to Find Triplets: For a triplet (i, j, k) to satisfy the condition
a==b
:if prefix[j−1]==prefix[k]
, it implies the condition is satisfied.
-
Time complexity:
$O(n^2)$ , where$n$ is the length of the array. The nested loops run in quadratic time. -
Space complexity:
$O(n)$ for the prefix XOR array.