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Power of Two

Created

2021/12/21 10:52

문제 번호

231

카테고리

Math

Bit Manipulation

Recursion

Power of Two - LeetCode

Given an integer n, return true if it is a power of two. Otherwise, return false . An integer n is a power of two, if there exists an integer x such that . Example 1: Example 2: Example 3: Constraints: Follow up: Could you solve it without loops/recursion?

https://leetcode.com/problems/power-of-two/description/

Code

제출 날짜	시간	메모리
2021/12/21	0 ms	2.2 MB

// 231. Power of Two
//
// https://leetcode.com/problems/power-of-two/

// isPowerOfTwo function returns the truth whether the given n is the number such that the power of two.
// Whether n is the power of two or not can be determined by only 64 iterating with Bit-Manipulation. (int type is 64-bit in Golang.)
// If n is the power of two, then the count of Bit-Manipulation with logical-and 1 should be 1.
func isPowerOfTwo(n int) bool {
	cnt := 0
	for i := 0; i < 64; i++ {
		if n&1 == 1 {
			cnt++
		}
		n = n >> 1
	}
	return cnt == 1
}
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