342. Power of Four
Easy
Given an integer (signed 32 bits), write a function to check whether it is a power of 4.
Example 1:
Input: 16
Output: true
Example 2:
Input: 5
Output: false
Follow up: Could you solve it without loops/recursion?
package leetcode.easy;
public class PowerOfFour {
public boolean isPowerOfFour(int num) {
if (num < 1) {
return false;
}
while (num % 4 == 0) {
num /= 4;
}
return num == 1;
}
@org.junit.Test
public void test() {
System.out.println(isPowerOfFour(16));
System.out.println(isPowerOfFour(5));
}
}