Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.
Note: The given integer is guaranteed to fit within the range of a 32-bit signed integer. You could assume no leading zero bit in the integer’s binary representation. Example 1: Input: 5 Output: 2 Explanation: The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2. Example 2: Input: 1 Output: 0 Explanation: The binary representation of 1 is 1 (no leading zero bits), and its complement is 0. So you need to output 0.
暴力求了32位的最大值，然后比较num最接近减去就是补码 代码：
public static int findComplement(int num) { int[] a = new int [33]; a[0] = 0; a[1] = 1; for (int i = 2; i <=32; i++) { a[i] = a[i-1]*2+1; } for (int i = 0; i <=32; i++) { if (num<=a[i]){ return a[i]-num; } } return 0; }