Every non-negative integer N has a binary representation. For example, 5 can be represented as "101" in binary, 11 as "1011" in binary, and so on. Note that except for N = 0, there are no leading zeroes in any binary representation.
The complement of a binary representation is the number in binary you get when changing every 1 to a 0 and 0 to a 1. For example, the complement of "101" in binary is "010" in binary.
For a given number N in base-10, return the complement of it's binary representation as a base-10 integer.
Example 1:
Input: 5 Output: 2 Explanation: 5 is "101" in binary, with complement "010" in binary, which is 2 in base-10. Example 2:
Input: 7 Output: 0 Explanation: 7 is "111" in binary, with complement "000" in binary, which is 0 in base-10. Example 3:
Input: 10 Output: 5 Explanation: 10 is "1010" in binary, with complement "0101" in binary, which is 5 in base-10.
Note:
0 <= N < 10^9
public class Solution {
public int BitwiseComplement(int N) {
if(N == 0){
return 1;
}
int ans = 0;
int curr = 1;
while(N != 0){
if(N % 2 == 0){
ans += curr;
}
N /= 2;
curr *= 2;
}
return ans;
}
}Time Complexity: O(n)
Space Complexity: O(1)
