Leetcode Questions Solutions Explained 2

Learn to add two numbers represented by linked lists in reverse order. Build the result with a dummy head, manage carries, and traverse both lists.

Explains how to search in rotated sorted array II with duplicates using binary search, handling pivot, identifying sorted/unsorted halves, and worst-case linear time.

Explains fizz buzz from one to n, using the modulo operator to check divisibility by three or five, and returning a list of strings like fizz, buzz, or fizzbuzz.

Solve the island perimeter problem (leetcode 463) by scanning a grid of 1s and 0s, adding four for each land and subtracting two for left or top neighbors.

Split a string into the maximum number of balanced strings by using a counter that increments on L and decrements on R, counting a substring when the counter hits zero.

Explore the binary tree right side view by applying a level order traversal with a queue, using breadth-first search to capture the rightmost node at each level (LeetCode 199).

Explore binary tree level order traversal using breadth-first search with a queue to visit nodes level by level from left to right, returning a list of lists for LeetCode 102.

Move all zeros to the end in place while preserving non-zero order. Use a two-pointer approach to swap non-zero elements forward, achieving linear time with no extra space.

Apply a two-pointer method to find the middle of a linked list, reverse the right half, and compare nodes to decide if it is a palindrome, as in LeetCode 234.

Identify self-dividing numbers between left and right bounds by checking each digit for zero and divisibility with a helper function, as seen in Google, Microsoft, Facebook, and LinkedIn interviews.

Compute the total sum, then scan to find the pivot index. Return the leftmost index where left and right sums match in linear time with constant space, or -1.