Solution 1 - Single Set Bit Check

A positive power of two has exactly one set bit, so n & (n - 1) is zero.

TimeComplexity: O(1)

SpaceComplexity: O(1)

""" 0231.1 - Power of Two - Solution 1 - Single Set Bit Check """

#####################################################################################
# Imports
#####################################################################################


#####################################################################################
# Classes
#####################################################################################
class Solution:
    def isPowerOfTwo(self, n: int) -> bool:
        return n > 0 and (n & (n - 1)) == 0


#####################################################################################
# Functions
#####################################################################################
def testcase():
    assert Solution().isPowerOfTwo(1)
    assert Solution().isPowerOfTwo(16)
    assert not Solution().isPowerOfTwo(3)
    print("tests passed")


#####################################################################################
# Main
#####################################################################################
if __name__ == "__main__":
    testcase()

/** 0231.1 - Power of Two - Solution 1 - Single Set Bit Check */

/////////////////////////////////////////////////////////////////////////////////////
// Classes
/////////////////////////////////////////////////////////////////////////////////////
class Solution {
    isPowerOfTwo(n) {
        return n > 0 && (n & (n - 1)) === 0;
    }
}

console.log(new Solution().isPowerOfTwo(16)); // true

/** 0231.1 - Power of Two - Solution 1 - Single Set Bit Check */

/////////////////////////////////////////////////////////////////////////////////////
// Classes
/////////////////////////////////////////////////////////////////////////////////////
class Solution {
    isPowerOfTwo(n: number): boolean {
        return n > 0 && (n & (n - 1)) === 0;
    }
}

console.log(new Solution().isPowerOfTwo(16)); // true

// 0231.1 - Power of Two - Solution 1 - Single Set Bit Check

package main

import "fmt"

func isPowerOfTwo(n int) bool {
	return n > 0 && (n&(n-1)) == 0
}

func main() {
	fmt.Println(isPowerOfTwo(16)) // true
}

// 0231.1 - Power of Two - Solution 1 - Single Set Bit Check

struct Solution;

impl Solution {
    fn is_power_of_two(n: i32) -> bool {
        n > 0 && (n & (n - 1)) == 0
    }
}

fn main() {
    assert!(Solution::is_power_of_two(16));
}

0231 - Power of Two

Solution 1 - Single Set Bit Check