// 342. Power of Four #include "leetcode.h" /* * 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' */ bool isPowerOfFour(int n) { return n > 0 && __builtin_popcount((unsigned)n) == 1 && !((n - 1) % 3); } int main() { printf("%d\n", isPowerOfFour(16)); // expect: 1 printf("%d\n", isPowerOfFour(5)); // expect: 0 printf("%d\n", isPowerOfFour(1)); // expect: 1 }