Number Complement
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.
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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.
Java Solution:
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class Solution {
public int findComplement(int num) {
int divisor = num;
Stack<Integer>mStack = new Stack<>();
while(divisor != 1){
int remainder = divisor % 2;
divisor /= 2;
remainder = remainder == 1 ? 0 : 1;
mStack.push(remainder);
}
mStack.push(0);
int sum = 0;
while(!mStack.isEmpty()){
sum = sum * 2 + mStack.pop();
}
return sum;
}
}
