Is Number of Steps to Reduce a Number to Zero easy or hard?

Number of Steps to Reduce a Number to Zero is classified as an Easy problem. The logic is straightforward simulation, but recognizing the connection to binary representation helps explain why the algorithm runs in logarithmic time.

Number of Steps to Reduce a Number to Zero Python/Java solution

Both Python and Java implementations follow the same logic: loop while the number is not zero, increment a counter, divide by two if the number is even, otherwise subtract one. The algorithm runs in O(log n) time and constant space across all languages.

How to solve Number of Steps to Reduce a Number to Zero in O(log n)?

Use a loop that continues while the number is greater than zero. If the number is even, divide it by two; if it is odd, subtract one. Because each step either removes a binary digit or clears a bit, the algorithm runs in O(log n) time.

What is the best approach for Number of Steps to Reduce a Number to Zero?

The iterative simulation approach is the best choice. Repeatedly check if the number is even or odd, divide by 2 for even numbers, and subtract 1 for odd numbers. Each operation reduces the number quickly, resulting in O(log n) time complexity and O(1) extra space.

Is Number of Steps to Reduce a Number to Zero asked at Google/Amazon/Meta?

This problem is categorized as an easy algorithm question and has appeared in interview preparation sets for companies like Amazon and Google. It is commonly used to evaluate basic problem-solving skills and understanding of binary operations.

What data structure is used in Number of Steps to Reduce a Number to Zero?

No specialized data structure is required. The solution relies on arithmetic operations and simple control flow. The underlying concept relates to bit manipulation because dividing by two corresponds to shifting bits right in binary.

What is the time complexity of Number of Steps to Reduce a Number to Zero?

The time complexity is O(log n). Each division by 2 removes one binary digit from the number, and each subtraction clears a trailing 1 bit. Since the number of bits in n is proportional to log n, the total number of operations grows logarithmically.

Description Hints 1 Solution Video 3:42

1342. Number of Steps to Reduce a Number to Zero

Easy86.0% acceptance6 companies

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: