String Matching in an Array · Interview Problem

Back to problems

Leetcode

Easy

Arrays

Strings

Hash Maps

String Matching in an Array

Find all words that appear as a substring of another word in the same list.

Acceptance 0%

Start Practice

Problem Statement

Given an array of strings, return every word that occurs as a contiguous substring of at least one other word in the array. Each matching word should appear once in the answer, regardless of how many superstrings contain it.

A word is considered a substring of another word if its characters appear consecutively inside that other word.

Input Format

A list of strings words.
words[i] is a non-empty lowercase string.

Output Format

Return all strings from words that are substrings of another string in words.
The order of the returned strings does not matter unless otherwise specified by the platform.

Constraints

$1 \le |words|$
Strings contain only lowercase English letters.
Individual string lengths are small enough for pairwise checking in an interview setting.

Premium problem context

Unlock deeper context for this problem

Premium adds guided hints, editorial links, similar variants, discussion resources, and concept maps so you can understand why a problem matters, not just solve it once.

Guided hints

Editorial and discussion links

Concept map and variants

Track your progress