Abstract / Summary

Find the string with the highest numeric value in an array of strings representing numbers.

Note

The full problem description, including helpful examples, can be found on LeetCode.

This problem is ranked as

and has an acceptance rate of about 74% (90k+ submissions).

Typical patterns to solve this problem:

• Array
• String

Every single line of code was written by me, 100% from scratch, between August 2023 and August 2024.
However, two years later I set up this website and used various AI tools to generate most of the walkthrough / explanations below.

See this dedicated page for more details.

Overview

The provided implementation defines a class Solution with a single method maximumValue. The method receives a list of strings and determines the greatest value among them according to two possible interpretations: a numeric value when the string consists solely of digits, or the length of the string otherwise. The algorithm iterates through the input once, maintaining a running maximum, and finally returns that maximum.

Key Steps and Corresponding Snippets

Result Initialization

At the start of the method a variable result is created and set to zero. This serves as the accumulator for the maximum value discovered during the traversal.

result = 0

Iterating Over the Input List

A for loop processes each element s in the supplied list strs. The loop body contains the logic that decides how to interpret each string.

for s in strs:
    ...

Determining Numeric Strings

Inside the loop the method uses the built-in string method isnumeric() to check whether the current string contains only digit characters. When the check succeeds, the string is converted to an integer and compared with the current maximum.

if s.isnumeric():
    result = max(result, int(s))

Handling Non-Numeric Strings

If the string fails the numeric test, its length is taken as the candidate value. The length is then compared with the current maximum using the same max function.

else:
    result = max(result, len(s))

Returning the Final Maximum

After all elements have been examined, the method returns the value stored in result.

return result

Edge Cases Addressed

The algorithm gracefully handles several boundary conditions without additional code:

• Empty Input List - When strs is empty the loop body never executes. Because result was initialized to zero, the method returns zero, which is a sensible default for “no values”.

• Empty Strings - An empty string is not numeric, so its length (zero) is considered. The maximum remains unchanged unless all other candidates are also zero.

• Strings with Leading Zeros - A string such as "00123" passes the isnumeric() test. Converting it with int() yields the integer 123, correctly ignoring the leading zeros while still contributing the numeric value.

• Very Large Numeric Strings - The conversion to int leverages Python’s arbitrary-precision integers, allowing the method to handle numbers far beyond typical 32-bit limits without overflow.

• Strings Containing Non-Digit Characters - Any alphabetic character, punctuation, or sign causes isnumeric() to return False. In those cases the length of the string is used, ensuring that mixed content does not raise an exception.

• Negative Numbers Represented as Strings - A string like "-42" fails the numeric test because the minus sign is not a digit. The method therefore treats it as a non-numeric string and uses its length, avoiding a ValueError from an invalid integer conversion.

Performance Optimizations Observed

The implementation exhibits several efficiency-focused choices:

• Single Pass Traversal - By updating the maximum during the iteration, the algorithm avoids the need for a secondary pass or auxiliary collections, keeping the work proportional to the number of input elements.

• Conditional Conversion - The conversion to an integer occurs only when the string is confirmed numeric. This prevents unnecessary parsing of non-numeric strings, saving CPU cycles.

• Use of Built-In Functions - Leveraging str.isnumeric(), len(), and max() taps into highly optimized C-level implementations provided by the Python runtime, which are faster than equivalent pure-Python loops.

• In-Place Accumulator - Maintaining a single scalar variable (result) eliminates memory overhead that would arise from storing intermediate results in a list or other container.

• Early Comparison - The max function is called with the current accumulator and the newly computed candidate, ensuring that only the larger of the two values is retained without extra conditional branching.

Overall, the code delivers a concise solution that balances readability with effective use of Python’s standard library to achieve good performance characteristics.

Imagine having a big box filled with cards that have either secret codes or long words written on them. You want to find the biggest number hidden in that box.

Inside the box, there is a tiny robot helper that picks up each card one by one. It looks closely at the card to see if it is just a plain number or if it is a word made of letters.

If the card has a number on it, the robot reads that number. If the card has letters instead, the robot counts how many letters are standing in a line to make the word.

The robot keeps a special notepad to remember the largest thing it has found so far. Every time it looks at a new card, it compares the current number or word count to whatever is already written on the notepad. If the new thing is bigger, the robot erases the old note and writes down the new, larger amount instead.

Once the robot has checked every single card in the box, the notepad shows the final winner.

Several LLMs ranked my code quality on a scale from 1 (very poor) to 10 (outstanding):

not analyzed yet

I wrote a basic crawler to find other solutions to that problem.
Obviously, I did that after I solved the problem myself.

In general, AlgoMonster and WalkCCC solutions are high-quality and always worth a look.
I haven't checked most of the other solutions, but they might be helpful as well.

And of course, the LeetCode forum is always a good place (or even the best) to look for alternative approaches.

(click on a column header to sort the table)

	author
author	solutions
www	AlgoMonster	Java				C++			Python		TS
	WalkCCC	Java				C++			Python
	leetcode.ca	Java			Go	C++	C	C#	Python	Rust	TS
	Progiez	Java				C++			Python
github	charles-wangkai	Java
	fartem		Ruby
	fsq					C++
	JoshCrozier			JS
	muhammadfarhankt				Go
	varunu28	Java
AlgoMonster	C++, Python, Java, TypeScript
WalkCCC	C++, Python, Java
leetcode.ca	C, C++, C#, Go, Java, Python, Rust, TypeScript
Progiez	C++, Java, Python
charles-wangkai	Java
fartem	Ruby
fsq	C++
JoshCrozier	JavaScript
muhammadfarhankt	Go
varunu28	Java

There are a few extra pages giving you some insights into my setup:

• Tech Stack - my development environment and tools
• AI - how AI helped me create this website (NOT solving the problems)
• Progress - progression over time
• Quality - code quality