693. Binary Number with Alternating Bits

Description

Given a positive integer, check whether it has alternating bits: namely, if two adjacent bits will always have different values.

Example 1:

Input: n = 5
Output: true
Explanation: The binary representation of 5 is: 101

Example 2:

Input: n = 7
Output: false
Explanation: The binary representation of 7 is: 111.

Example 3:

Input: n = 11
Output: false
Explanation: The binary representation of 11 is: 1011.

Constraints:

class Solution {
    public boolean hasAlternatingBits(int n) {
        n ^= (n >> 1);
        return (n & (n + 1)) == 0;
    }
}

class Solution {
public:
    bool hasAlternatingBits(int n) {
        n ^= (n >> 1);
        return (n & ((long) n + 1)) == 0;
    }
};

class Solution:
    def hasAlternatingBits(self, n: int) -> bool:
        n ^= n >> 1
        return (n & (n + 1)) == 0

func hasAlternatingBits(n int) bool {
	n ^= (n >> 1)
	return (n & (n + 1)) == 0
}

impl Solution {
    pub fn has_alternating_bits(n: i32) -> bool {
        let t = n ^ (n >> 1);
        (t & (t + 1)) == 0
    }
}