342. Power of Four 发表于 2022-05-22 Bit1234567public boolean isPowerOfFour(int n) { if (n <= 0) { return false; } return (n & (n - 1)) == 0 && (n & 0b01010101010101010101010101010101) != 0;} Math123456789class Solution { public boolean isPowerOfFour(int n) { if (n <= 0) { return false; } return (n & (n - 1)) == 0 && n % 3 == 1; }} Reference342. Power of Four