LeetCode Entry

3514. Number of Unique XOR Triplets II

24.07.2026 medium 2026 kotlin rust

Uniq xor of tripplets in array

3514. Number of Unique XOR Triplets II medium substack youtube

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Problem TLDR

Uniq xor of tripplets in array

Intuition

The number of uniq xors is very compressable, we can assume that converting n^2 pairwise to set gives a small colleciton

Approach

• to speed up more use boolean array/bitset

Complexity

• Time complexity: \(O(n^2)\)

• Space complexity: \(O(n^2)\)

Code

    fun uniqueXorTriplets(n: IntArray) = buildSet {
        for (x in buildSet { for (x in n) for (y in n) add(x xor y) })
            for (y in n) add(x xor y) }.size

    pub fn unique_xor_triplets(mut n: Vec<i32>) -> i32 {
        n.sort_unstable(); n.dedup();
        let mut s = [false; 1 << 12]; let mut t = s.clone();
        for i in 0..n.len() { for j in i..n.len() { s[(n[i] ^ n[j]) as usize] = true }}
        for x in 0..s.len() { if s[x] { for &v in &n { t[x ^ v as usize] = true }}}
        t.iter().filter(|&&b| b).count() as _
    }