publicclass{ * Given an integer (signed 32 bits), write a function to check whether it is a power of 4. * 判断一个数是否是4的幂, 4 ^ x = num; * * Example 1: * * Input: 16 * Output: true * Example 2: * * Input: 5 * Output: false * Follow up: Could you solve it without loops/recursion? */ publicbooleanisPowerOfFour(int num){ if (num == 1) returntrue; if (num % 2 == 1) returnfalse; while(num % 4 == 0){ num = num/4; } if (num != 1){ returnfalse; } returntrue; } }
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