1442. Count Triplets That Can Form Two Arrays of Equal XOR

[mah-shamim]

Discussed in #275

^{Originally posted by mah-shamim August 9, 2024}
Given an array of integers arr.

We want to select three indices i, j and k where (0 <= i < j <= k < arr.length).

Let's define a and b as follows:

• a = arr[i] ^ arr[i + 1] ^ ... ^ arr[j - 1]
• b = arr[j] ^ arr[j + 1] ^ ... ^ arr[k]

Note that ^ denotes the bitwise-xor operation.

Return the number of triplets (i, j and k) Where a == b.

Example 1:

• Input: arr = [2,3,1,6,7]
• Output: 4
• Explanation: The triplets are (0,1,2), (0,2,2), (2,3,4) and (2,4,4)

Example 2:

• Input: arr = [1,1,1,1,1]
• Output: 10

Constraints:

• 1 <= arr.length <= 300
• 1 <= arr[i] <= 108