# LeetCode 1342. Number of Steps to Reduce a Number to Zero

## Description

https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero/

Given a non-negative integer `num`, return the number of steps to reduce it to zero. If the current number is even, you have to divide it by 2, otherwise, you have to subtract 1 from it.

Example 1:

```Input: num = 14
Output: 6
Explanation:
Step 1) 14 is even; divide by 2 and obtain 7.
Step 2) 7 is odd; subtract 1 and obtain 6.
Step 3) 6 is even; divide by 2 and obtain 3.
Step 4) 3 is odd; subtract 1 and obtain 2.
Step 5) 2 is even; divide by 2 and obtain 1.
Step 6) 1 is odd; subtract 1 and obtain 0.
```

Example 2:

```Input: num = 8
Output: 4
Explanation:
Step 1) 8 is even; divide by 2 and obtain 4.
Step 2) 4 is even; divide by 2 and obtain 2.
Step 3) 2 is even; divide by 2 and obtain 1.
Step 4) 1 is odd; subtract 1 and obtain 0.
```

Example 3:

```Input: num = 123
Output: 12
```

Constraints:

• `0 <= num <= 10^6`

## Explanation

Just by implementing the step instructions and it would work.

## Python Solution

``````class Solution:
def numberOfSteps (self, num: int) -> int:
steps = 0

while num > 0:
if num % 2 == 0:
num = num // 2
else:
num -= 1
steps += 1

return steps``````
• Time Complexity: O(N)
• Space Complexity: O(1)