# Finding Number Complements using Java ## The problem

Given a positive integer `num`, output its complement number. The complement strategy is to flip the bits of its binary representation.

Example 1:

```Input: num = 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: num = 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.```

Constraints:

• The given integer `num` is guaranteed to fit within the range of a 32-bit signed integer.
• `num >= 1`
• You could assume no leading zero bit in the integer’s binary representation.

## The code

```// Our method that takes in an `int` and returns an `int`
public int findComplement(int num) {
// Duplicate the input for reference
int originalNum = num;

// Set a variable for looping on an index
long i = 1;
// Loop while `i` is less or equal to `originalNum`
while(i<=originalNum) {
// Shift the variables
num ^= i;
i <<= 1;
}
// Return the resultant `num`
return num;
}
```
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