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

#### Easy

***

Given an integer `num`, return *the number of steps to reduce it to zero*.

In one step, 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 <= 106`

```python
class Solution:
    def numberOfSteps(self, num: int) -> int:
        if num == 0:
            return 0
        remain = num // 2 if num%2 == 0 else num-1
        return 1 + self.numberOfSteps(remain)
```