/* 

You are given a string S of length N which encodes a non-negative number V in a binary form. Two types of operations may be performed on it to modify its value:

​

if V is odd, subtract 1 from it;

if V is even, divide it by 2.

These operations are performed until the value of V becomes 0.

​

For example, if string S = "011100", its value V initially is 28. The value of V would change as follows:

​

V = 28, which is even: divide by 2 to obtain 14;

V = 14, which is even: divide by 2 to obtain 7;

V = 7, which is odd: subtract 1 to obtain 6;

V = 6, which is even: divide by 2 to obtain 3;

V = 3, which is odd: subtract 1 to obtain 2;

V = 2, which is even: divide by 2 to obtain 1;

V = 1, which is odd: subtract 1 to obtain 0.

Seven operations were required to reduce the value of V to 0.

​

Write a function:

​

class Solution { public int solution(String S); }

​

that, given a string S consisting of N characters containing a binary representation of the initial value V, returns the number of operations after which its value will become 0.

*/

​

using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(solution("011100") == 7);

        Console.WriteLine(solution("111") == 5);

        Console.WriteLine(solution("111010101111") == 22);

        Console.WriteLine(solution("1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111") == 217);

    }

​

    public static int solution(string S) {

        // Get out of binary space, convert it to an int for easier use.

        int a = Convert.ToInt32(S, 2);

​

        // track n operations required to reach 0;

        int operations = 0;

​

        while(a != 0){

            if(a%2 == 0){

                a = a / 2;

            }else{

                a = a - 1;

            }

            operations++;

        }

        // return op count

        return operations;

​

        /*

            After hitting optimisation issues with this I looked into performing binary arithmetic

            on the string itself without converting to a integer which would've improved the performance.

            Timed out on this one, but very interesting question to think about.

        */

    }

}