How should I practice Alphabetically Maximum Substring?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Oracle phone screen problems in FastPrep.

Is Alphabetically Maximum Substring associated with Oracle?

FastPrep tags this as a Oracle phone screen coding practice problem when the problem catalog has that company and stage context.

Problem · String

Alphabetically Maximum Substring

Learn this problem

● Hard

OracleFULLTIMEPHONE SCREEN

Problem statement

Given a string s containing lowercase English letters, return its lexicographically greatest non-empty substring.

A substring is a contiguous sequence of characters from s. String a is lexicographically greater than string b when either:

At the first position where they differ, a has the greater character.
b is a proper prefix of a.

Function

alphabeticallyMaximumSubstring(s: String) → String

Examples

Example 1

s = "abab"return = "bab"

The substring bab begins with b, so it is greater than every substring beginning with a. It is also greater than the one-character substring b because b is its proper prefix.

Example 2

s = "leetcode"return = "tcode"

The only occurrence of the greatest character t begins the substring tcode, which is therefore greater than every other substring.

Example 3

s = "aaaa"return = "aaaa"

Every candidate contains only a. The full string is greatest because every shorter candidate is its proper prefix.

Constraints

1 <= s.length <= 200000
s contains only lowercase English letters.