Is Remove Trailing Zeros From a String easy or hard?

Remove Trailing Zeros From a String is categorized as an Easy problem. It focuses on basic string traversal and boundary conditions rather than complex algorithms or data structures.

Remove Trailing Zeros From a String Python/Java solution

In Python or Java, iterate from the last index of the string and decrement the pointer while the character equals '0'. After the loop ends, return the substring up to the final index. The implementation is short and runs in O(n) time with constant extra space.

How to solve Remove Trailing Zeros From a String in O(n)?

Start from the last character of the string and move backward while characters equal '0'. When the first non-zero digit appears, stop the scan and return the substring from index 0 to that position. Each character is checked at most once, giving O(n) time complexity.

What is the best approach for Remove Trailing Zeros From a String?

The best approach is scanning the string from the end until the first non-zero character appears. Once found, return the substring up to that index. This solution runs in O(n) time and uses O(1) extra space, making it both simple and optimal.

Is Remove Trailing Zeros From a String asked at Google/Amazon/Meta?

String manipulation problems like this appear frequently in coding interviews at companies such as Amazon, Google, and Meta. While the exact problem may vary, identifying and trimming characters from the end of a string is a common interview pattern.

What data structure is used in Remove Trailing Zeros From a String?

The problem primarily uses basic string operations. The algorithm relies on index traversal of a string rather than specialized data structures, though the logic resembles a backward pointer scan commonly used in two-pointer techniques.

What is the time complexity of Remove Trailing Zeros From a String?

The optimal algorithm runs in O(n) time, where n is the length of the string. In the worst case you scan the entire string when it contains only zeros or when no trailing zeros exist. Space complexity can be O(1) if you only track an index while scanning backward.

Description Hints 1 Solution Video 4:15

2710. Remove Trailing Zeros From a String

Easy79.5% acceptance

Given a positive integer num represented as a string, return the integer num without trailing zeros as a string.

Example 1:

Input: num = "51230100"
Output: "512301"
Explanation: Integer "51230100" has 2 trailing zeros, we remove them and return integer "512301".

Example 2:

Input: num = "123"
Output: "123"
Explanation: Integer "123" has no trailing zeros, we return integer "123".

Constraints:

1 <= num.length <= 1000
num consists of only digits.
num doesn't have any leading zeros.

Topics

String

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Hint 1

Find the last non-zero digit in num.

4:15

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2710. Remove Trailing Zeros From a String

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