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Solution: Count Triplets That Can Form Two Arrays of Equal XOR

Explore how to count triplets in an integer array such that the XOR of two subarrays is equal. This lesson teaches applying bitwise XOR operations, prefix XOR optimization, and hash map usage to improve from a naive O(n³) to an efficient O(n) solution. Gain practical skills in bitwise manipulation and algorithm optimization for coding interviews.

Statement

Given an array of integers, arr, we need to find three indices, i, j, and k, such that 00\leq i << j \leq k << arr.length.

We define two values, a and b, as follows:

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

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

Note: ^ denotes the bitwise XOR operation.

Return the count of triplets (i, j, k) for which a is equal to b.

Constraints:

  • 11 \leq ...