ComplementofBase10Integer.java

// TC : O(1)
class Solution {

	public int findComplement(int num) {
		if (num == 0) {
			return 1;
		}
		int multi = 1;
		int newNo = 0;

		while (num != 0) {
			int binaryRep = (num % 2 == 0) ? 1 : 0;
			num = num / 2;
			newNo = binaryRep * multi + newNo;
			multi = multi * 2;
		}
		return newNo;
	}

	public int findComplement(int num) {
		if (num == 0) {
			return 1;
		}
		int no = 0;
		int power = 0;

		while (no < num) {
			no += Math.pow(2, power);
			power++;
		}

		return no - num;
	}
}