#### QUESTION:

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`

#### EXPLANATION:

这个比较简单，直接看代码就可以了。

#### SOLUTION:

```
class Solution {
public int bitwiseComplement(int N) {
boolean found = false;
String result = "";
String bin = Integer.toBinaryString(N);
for (char c:bin.toCharArray()){
if(c=='1') result = result+0;
else result = result+1;
}
return Integer.parseInt(result,2);
}
}
```