This post is part of the Algorithms Problem Solving series.
Problem description
This is the Number of Steps to Reduce a Number to Zero problem. The description looks like this:
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.
Examples
Input: num = 14
Output: 6
Input: num = 8
Output: 4
Solution
The solution is to do the subtraction or the division until the number is zero.
We can do this by using a while loop. If it is zero, the loop will stop. If it is not, keep the calculation.
def reduce_number(num):
if num % 2 == 0:
return num / 2
else:
return num - 1
def number_of_steps(num):
counter = 0
while num:
counter += 1
num = reduce_number(num)
return counter
I also add a separate function called reduce_number
to be responsible to the calculation.
Resources
- Learning Python: From Zero to Hero
- Algorithms Problem Solving Series
- Big-O Notation For Coding Interviews and Beyond
- Learn Python from Scratch
- Learn Object-Oriented Programming in Python
- Data Structures in Python: An Interview Refresher
- Data Structures and Algorithms in Python
- Data Structures for Coding Interviews in Python
- One Month Python Course
- Big-O Notation For Coding Interviews and Beyond
- Learn Python from Scratch
- Learn Object-Oriented Programming in Python
- Data Structures in Python: An Interview Refresher
- Data Structures and Algorithms in Python
- Data Structures for Coding Interviews in Python
- One Month Python Course