Add two numbers represented as linked lists. Handle carry when sum > 9. Time complexity: O(max(N, M)), space complexity: O(max(N, M)).

Implementing MinStack in JavaScript: Use an auxiliary stack (minStack) to store the minimum element at each step, enabling O(1) time complexity for getMin(). Push and pop operations remain O(1).

We loop through chars of s, if its a closing bracket we compare with last element in stack, it should be appropriate as define in map otherwise we return false. JavaScript Code: https://example.com/jscode

Merge Intervals: Sort balloons by start pos, merge overlaps with single arrow, update last interval on overlap. Min arrows = size of merged intervals list. Time: O(n log n), Space: O(n).

Grouping Anagrams using Sorting takes O(nlogn * m) time complexity, but can be optimized to O(n * m) with Hashmap by counting character frequencies.

JavaScript Map Basics: A Map stores key-value pairs & maintains insertion order. Use set(), get(), has(), delete() methods. Iterate with for...of or forEach(). Ideal for frequent updates & maintaining order.

Cell State Mapping in Game of Life algorithm: Alive (1), Dead (0), Transitional Values (2, 3). Rules: Cell remains alive with 2 or 3 neighbors, dies with < 2 or > 3. Dead cell becomes alive with exactly 3 neighbors.

Minimum Window Substring: Find min window in `s` containing all chars of `t`. Use sliding window approach with freq maps. Expand & shrink window to find smallest valid substring.

Optimize string length with `lengthOfLongestSubstring` function. Uses Set to track unique substrings and slide window approach for efficient solution.

Javascript Code: longestCommonPrefix function iterates through strings to find common prefix, trimming at first mismatch.