Grokking the Coding Interview: Patterns for Coding Questions
Ask Author
Back to course home

0% completed

Vote For New Content
Remove All Adjacent Duplicates In String (easy)
Table of Contents

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible

Problem Statement

You are given a string s consisting of lowercase English letters. A duplicate removal consists of choosing two adjacent and equal letters and removing them.

We repeatedly make duplicate removals on s until we no longer can.

Return the final string after all such duplicate removals have been made.

Examples

    • Input: s = "abccba"
    • Output: ""
    • Explanation: First, we remove "cc" to get "abba". Then, we remove "bb" to get "aa". Finally, we remove "aa" to get an empty string.
    • Input: s = "foobar"
    • Output: "fbar"
    • Explanation: We remove "oo" to get "fbar".
    • Input: s = "fooobar"
    • Output: "fobar"
    • Explanation: We remove the pair "oo" to get "fobar".
    • Input: s = "abcd"
    • Output: "abcd"
    • Explanation: No adjacent duplicates so no changes.

Constraints:

  • 1 <= s.length <= 10<sup>5</sup>
  • s consists of lowercase English letters.

Try it yourself

Try solving this question here:

Python3
Python3
. . . .

.....

.....

.....

Like the course? Get enrolled and start learning!

Table of Contents

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible

Contents are not accessible