Power Of Four Problem
Description
LeetCode Problem 342.
Given an integer n, return true if it is a power of four. Otherwise, return false.
An integer n is a power of four, if there exists an integer x such that n == 4^x.
Example 1:
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Input: n = 16
Output: true
Example 2:
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Input: n = 5
Output: false
Example 3:
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Input: n = 1
Output: true
Constraints:
- -2^31 <= n <= 2^31 - 1
Sample C++ Code
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class Solution {
public:
bool isPowerOfFour(int num) {
if (num <= 0)
return false;
while (num > 1) {
if ((num & 3) != 0)
return false;
num = num >> 2;
}
return true;
}
};