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// 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
}
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