Strings · Coding problem

Roman to Integer

A free coding problem from the String Symbol Mapping skill. Read it here, then solve it in the app in Java or Python.

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  • Easy
  • Coding problem
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  • Java and Python

The problem

Given a Roman numeral s, convert it to an integer.

Example

Input:  s = "MMXXVI"
Output: 2026

Roman numerals use subtractive notation: a smaller symbol written just before a larger one is subtracted from it (IV = 4, CM = 900).

Constraints

  • 1 <= s.length <= 15
  • s contains only the characters I V X L C D M
  • s is a valid Roman numeral in the range [1, 3999]

How it's graded

  • Run checks your code against the examples. Submit also runs a hidden suite in four groups - basic cases, edge cases, random inputs and performance tests at the size limit - and shows which groups pass, never the hidden inputs.
  • Stuck? Hints come in four steps, from a nudge to a code skeleton, each costing part of the points.
  • Once you pass, you see the approaches from brute force to optimal, and where your solution lands among them.

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