201. Bitwise AND of Numbers Range

二刷 07/2022

Version #2 Turn off the right most bit of the larger number

Time O(1)

Space O(1)

Runtime: 7 ms, faster than 85.09% of Java online submissions for Bitwise AND of Numbers Range.

Memory Usage: 44.5 MB, less than 25.77% of Java online submissions for Bitwise AND of Numbers Range.

class Solution {

    public int rangeBitwiseAnd(int left, int right) {

        while (left < right) {

            right = right & (right - 1);

        }

        return left & right;

    }

}

Ref: https://www.cnblogs.com/grandyang/p/4431646.html
一刷
// Find the common prefix of m and n
100.00 %
class Solution {
    public int rangeBitwiseAnd(int m, int n) {
        int bit = 0;
        while ((m >> bit) != (n >> bit)) {
            bit++;
        }
        return (m >> bit) << bit;
    }
}