Available question text
Given an integer array, count the number of index triplets whose bitwise XOR has an even number of 1-bits. Key insight: parity of popcount is preserved under XOR, so you can reduce the problem to counting triplets by popcount parity (all three even, or exactly two odd + one even) and compute counts combinatorially for O(n) time.
Related questions
Continue with questions that share topics or the same question type.
Sources · 1 reference
These records explain where the question appears. A company tag or candidate report does not guarantee a future interview question.
Hello Interview · 1 record
No company association
Leetcode 3215. Count Triplets with Even XOR Set Bits II
Reported date not specified · 0 source reports
Source snapshot: Nov 12, 2026
View source