Post

1520 Number Of Steps To Reduce A Number In Binary Representation To One

1520 Number Of Steps To Reduce A Number In Binary Representation To One

Number of Steps to Reduce a Number in Binary Representation to One image

Given the binary representation of an integer as a string s, return the number of steps to reduce it to *1 under the following rules*:

If the current number is even, you have to divide it by 2.

If the current number is odd, you have to add 1 to it.

It is guaranteed that you can always reach one for all test cases.

 

Example 1:

1
2
3
4
5
6
7
8
9
10
11
**Input:** s = "1101"
**Output:** 6
**Explanation:** "1101" corressponds to number 13 in their decimal representation.
Step 1) 13 is odd, add 1 and obtain 14. 
Step 2) 14 is even, divide by 2 and obtain 7.
Step 3) 7 is odd, add 1 and obtain 8.
Step 4) 8 is even, divide by 2 and obtain 4.  
Step 5) 4 is even, divide by 2 and obtain 2. 
Step 6) 2 is even, divide by 2 and obtain 1.  

Example 2:

1
2
3
4
5
6
**Input:** s = "10"
**Output:** 1
**Explanation:** "10" corresponds to number 2 in their decimal representation.
Step 1) 2 is even, divide by 2 and obtain 1.  

Example 3:

1
2
3
4
**Input:** s = "1"
**Output:** 0

 

Constraints:

1
2
3
1 <= s.length <= 500
s consists of characters '0' or '1'
s[0] == '1'
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

class Solution:
    def numSteps(self, s: str) -> int:
        a = int(s, 2)
        result = 0
        
        while (a != 1):
            #print(a)
            result += 1
            if a % 2 == 0:
                a = a // 2
            else:
                a = a + 1
        return result



This post is licensed under CC BY 4.0 by the author.