1404. Number of steps to reduce a number in binary representation to one

//1404. Number of steps to reduce a number in binary representation to one

class Solution {
    public int numSteps(String s) {
        int cnt = 0;
        int carry = 0;

        for(int i = s.length() - 1; i >= 1; i--) {
            int num = s.charAt(i) -'0';

            if(num == 0 && carry == 0) {
                cnt++;
            }
            else if(num == 1 && carry == 1) {
                cnt++;
                carry = 1;
            }
            else{
                cnt += 2;
                carry = 1;
            }
        }

        if(carry == 1) {
            cnt++;
        }
        
        return cnt;
    }
}