Is Remove Zeros in Decimal Representation easy or hard?

Remove Zeros in Decimal Representation is generally classified as an Easy problem. The logic involves basic digit processing using either string traversal or simple arithmetic operations, making it approachable for beginners practicing simulation or math-based problems.

Remove Zeros in Decimal Representation Python/Java solution

In Python or Java, the typical solution converts the number to a string, iterates through characters, skips '0', and reconstructs the result. This approach takes O(d) time and is concise in both languages using built-in string operations.

How to solve Remove Zeros in Decimal Representation in O(n)?

Process the digits sequentially and skip zeros. One method converts the number to a string and filters characters. Another uses repeated modulo and division operations (n % 10 and n / 10) to extract digits and rebuild the result. Both approaches scan digits once, giving O(d) time complexity.

What is the best approach for Remove Zeros in Decimal Representation?

The most practical approach is string-based simulation. Convert the integer to a string, iterate through each character, skip '0', and rebuild the number from the remaining digits. This runs in O(d) time where d is the number of digits and is simple to implement in most languages.

Is Remove Zeros in Decimal Representation asked at Google/Amazon/Meta?

Problems involving digit manipulation and simulation frequently appear in interviews at large tech companies. While this exact problem may vary, the underlying techniques—string processing and mathematical digit extraction—are common in coding interviews at companies like Google, Amazon, and Meta.

What data structure is used in Remove Zeros in Decimal Representation?

The problem mainly uses strings or simple integer variables. The string approach stores digits temporarily while filtering out '0'. The mathematical approach uses only integer arithmetic, making it a constant-space solution without additional data structures.

What is the time complexity of Remove Zeros in Decimal Representation?

The optimal solution runs in O(d) time, where d is the number of digits in the integer. Each digit is processed exactly once while filtering out zeros. Space complexity is O(d) for the string approach or O(1) if you rebuild the number using arithmetic operations.

Description Hints 1 Solution Video 1:45

3726. Remove Zeros in Decimal Representation

Easy75.7% acceptance

You are given a positive integer n.

Return the integer obtained by removing all zeros from the decimal representation of n.

Example 1:

Input: n = 1020030

Output: 123

Explanation:

After removing all zeros from 1020030, we get 123.

Example 2:

Input: n = 1

Output: 1

Explanation:

1 has no zero in its decimal representation. Therefore, the answer is 1.

Constraints:

1 <= n <= 10¹⁵

Topics

Math Simulation

Hints open one at a time

Hint 1

Convert to a string and filter out the '0' characters.

1:45

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1class Solution:
2    def removeZeros(self, n: int) -> int:
3        

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