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This approach involves successively dividing the number n by 4 to check if it results in 1. If n is a power of four, repeatedly dividing it by 4 should eventually reduce it to 1 with no remainder.
Time Complexity: O(log4 n) due to repeated division.
Space Complexity: O(1) because no additional space is used.
1#include <iostream>
2
3bool isPowerOfFour(int n) {
4 if (n <= 0) return false;
5 while (n % 4 == 0) {
6 n /= 4;
7 }
8 return n == 1;
9}Similar to the C version, this C++ function checks divisibility by 4 and continuously divides by 4 until n reaches 1, confirming it's a power of four.
This approach harnesses logarithms to determine if a number is a power of four. For a number n to be a power of four, the logarithm base 4 of n should be an integer. Utilizing the change of base formula, this can be checked without directly using base 4 logarithm functions.
Time Complexity: O(1) as logarithmic operations are constant time.
Space Complexity: O(1).
1functionBy leveraging JavaScript's Math methods, it determines the power of four status by computing logarithmic values and comparing with their floored versions.