Leetcode - Number of Steps to Reduce a Number to Zero Solution
Poor Man
- Published
- Updated
- Reading time
- 1 min read
- Length
- 197 words
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:
Text
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:
Text
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:
Text
Input: num = 123
Output: 12Constraints:
0 <= num <= 10^6
Solution in Python#
Python
class Solution:
def numberOfSteps (self, num: int) -> int:
steps = 0
while num:
if num%2:
num-=1
else:
num//=2
steps+=1
return steps