Why BigInt is useful in solving "medium" LeetCode interview questions  Summary and Q&A
TL;DR
The content explains how to add two nonnegative integers represented by reversed linked lists.
Key Insights
 👂 The problem illustrates a common scenario in coding interviews where unique data structures, like linked lists, must be manipulated.
 👂 Understanding linked list traversal and recursion is crucial for effectively managing and converting linked lists during operations.
 🍵 Utilizing builtin language features, like BigInt in JavaScript, can simplify complex problems that involve handling large numbers.
 👂 The conversion between data formats (string, linked list) is vital when tackling coding challenges that involve custom structures.
 ⚖️ A balance between performance and memory usage should be considered when developing solutions for algorithmic problems.
 🥺 Leveraging community discussions and code reviews after implementing a solution can lead to improved techniques and understanding.
 🧑💼 The approach described demonstrates that multiple methods can solve the same problem, each with unique advantages and tradeoffs.
Transcript
all right so I'm doing another Elite code problem um this one I I did saw beforehand I'm going to explain my solution but we're going to kind of implement it together so you can kind of learn from this if you're trying to practice for interview questions or just kind of understand how do you solve these programming challenging challenges so this on... Read More
Questions & Answers
Q: What is the main challenge presented by the problem of adding two numbers represented as linked lists?
The main challenge is the representation of the numbers in reverse order and their potential length, which can be up to 100 digits. This length prevents the use of standard integer operations, making it necessary to use alternative methods like string manipulation or BigInt in JavaScript to perform addition without overflow errors.
Q: Why is the author using BigInt for this problem?
The author uses BigInt because standard numeric types cannot accurately handle numbers as large as 100 digits. BigInt in JavaScript allows for mathematical operations on arbitrarily large integers. This results in more manageable code for adding the two numbers represented by the linked lists, preventing errors that would occur with traditional integer types.
Q: Can you explain the function being implemented to convert a linked list into a string?
The implemented function traverses the input linked list recursively, concatenating each node's value into a string until the entire list is processed. Base cases prevent errors by returning an empty string when the end of the list is reached. This string representation is then used for addition.
Q: What final step must be taken after obtaining the sum of the two numbers?
After calculating the sum using BigInt, the next step is to convert this sum back into a linked list format, ensuring the result maintains the required representation of digits in reverse order for the final output. The author details the implementation of a function for this conversion.
Summary & Key Takeaways

The problem involves adding two nonnegative integers stored in reverse order as linked lists, which can be extensive in length.

The author suggests converting the linked lists to strings and using JavaScript's BigInt to perform the addition, facilitating manipulations involving large numbers.

A final linked list result needs to be formed and returned, which involves reversing the string representation of the sum before converting it back into a linked list format.