LeetCode 3209: Number of Subarrays With AND Value of K Solution

Master LeetCode problem 3209 (Number of Subarrays With AND Value of K), a hard challenge, with our optimized solutions in Java, C++, and Python. Explore detailed explanations, test your code in our interactive editor, and prepare for coding interviews.

3209. Number of Subarrays With AND Value of K

Hard

Array Binary Search Bit Manipulation Segment Tree

Problem Explanation

Explanation

To solve this problem, we can iterate through the array while keeping track of the prefix AND value. As we iterate, we also maintain a mapping of prefix AND values and their frequencies. For each element in the array, we check how many subarrays ending at that element have an AND value equal to k. This can be calculated based on the prefix AND values we have seen so far.

Time complexity: O(n) where n is the length of the input array nums. Space complexity: O(n) to store the prefix AND values and their frequencies.

Solution Code

class Solution {
    public int countKSubarrays(int[] nums, int k) {
        Map<Integer, Integer> prefixAndFreq = new HashMap<>();
        prefixAndFreq.put(0, 1);
        
        int result = 0;
        int prefixAnd = 0;
        
        for (int num : nums) {
            prefixAnd &= num;
            result += prefixAndFreq.getOrDefault(prefixAnd ^ k, 0);
            prefixAndFreq.put(prefixAnd, prefixAndFreq.getOrDefault(prefixAnd, 0) + 1);
        }
        
        return result;
    }
}

Try It Yourself

Loading code editor...

Frequently Asked Questions

How to solve LeetCode 3209 (Number of Subarrays With AND Value of K)?

This page provides optimized solutions for LeetCode problem 3209 (Number of Subarrays With AND Value of K) in Java, C++, and Python, along with a detailed explanation and an interactive code editor to test your code.

What is the time complexity of LeetCode 3209 (Number of Subarrays With AND Value of K)?

The time complexity for LeetCode 3209 (Number of Subarrays With AND Value of K) varies by solution. Check the detailed explanation section for specific complexities in Java, C++, and Python implementations.

Can I run code for LeetCode 3209 on DevExCode?

Yes, DevExCode provides an interactive code editor where you can write, test, and run your code for LeetCode 3209 in Java, C++, or Python.

Back to LeetCode Solutions