Decode String

Category

Stack

Checkbox

Difficulty

Medium

Index

Key Ideas

The key idea to solve the "Decode String" problem is to use a stack to keep track of the current string and the number of times it needs to be repeated.

Problem Number

394

Problem Summary

Problem Summary: The "Decode String" problem (Problem Number 394) is a medium difficulty problem in the Stack category. Given an encoded string, the task is to decode it and return the decoded string. Key pitfalls to watch out for include handling nested encodings, managing the repetition factor, and correctly reconstructing the decoded string using a stack or recursion.

Solution Summary

The best solution to solve the Decode String problem in LeetCode-75 curated list involves using a stack and recursion. The main idea is to iterate through the given string and process each character. When encountering a digit, we push it onto the stack to keep track of the repetition count. When encountering an opening bracket, we push the current result and repetition count onto the stack and start a new result and repetition count. When encountering a closing bracket, we pop the repetition count and the previous result from the stack, and append the current result to the previous result the required number of times. Finally, we return the decoded string as the result. This approach effectively handles nested brackets and ensures the correct decoding of the string.