2021-12-21 Daily-Challenge

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In: DailyChallenge

Today I have done leetcode's December LeetCoding Challenge with cpp.

December LeetCoding Challenge 21

Description

Power of Two

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 x such that n == 2x.

Example 1:

Input: n = 1
Output: true
Explanation: 20 = 1

Example 2:

Input: n = 16
Output: true
Explanation: 24 = 16

Example 3:

Input: n = 3
Output: false

Constraints:

  • -231 <= n <= 231 - 1

Follow up: Could you solve it without loops/recursion?

Solution

class Solution {
public:
  bool isPowerOfTwo(int n) {
    return n > 0 && !(n & (n - 1));
  }
};

// Accepted
// 1108/1108 cases passed (0 ms)
// Your runtime beats 100 % of cpp submissions
// Your memory usage beats 69.12 % of cpp submissions (5.9 MB)
Algorithm