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

Explore how to solve the problem of counting triplets in an array where the XOR of two subarrays are equal. Understand the use of prefix XOR and hash maps to optimize the solution from O(n^3) to O(n) time complexity. This lesson teaches efficient bitwise manipulation and algorithm design useful in 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 arr.length 300\leq 300

  • 11 \leq ...