BitwiseAndOfNumbersRange.java

package bit_manipulation.medium;

/***
 * Problem 201 in Leetcode: https://leetcode.com/problems/bitwise-and-of-numbers-range/
 *
 * Given two integers left and right that represent the range [left, right],
 * return the bitwise AND of all numbers in this range, inclusive.
 *
 * Example 1:
 * Input: left = 5, right = 7
 * Output: 4
 *
 * Example 2:
 * Input: left = 0, right = 0
 * Output: 0
 *
 * Example 3:
 * Input: left = 1, right = 2147483647
 * Output: 0
 */

public class BitwiseAndOfNumbersRange {
    public static void main(String[] args) {
        int left = 5, right = 2147483647;

        System.out.println("Bitwise AND of: " + bitwiseAndOfFrom(left, right));
    }

    private static int bitwiseAndOfFrom(int left, int right) {
        int count = 0;

        while (left != right) {
            left >>= 1;
            right >>= 1;
            count++;
        }

        return left << count;
    }
}