LeetCode – Reorder List (Java)

Given a singly linked list L: L0→L1→ … →Ln-1→Ln, reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… For example, given {1,2,3,4}, reorder it to {1,4,2,3}. You must do this in-place without altering the nodes’ values. Java Solution Because the problem requires “in-place” operations, we can only change their pointers, not creating a new list. This problem can be solved … Read more

Leetcode – Longest Palindromic Substring (Java)

Finding the longest palindromic substring is a classic problem of coding interview. This post summarizes 3 different solutions for this problem. 1. Dynamic Programming Let s be the input string, i and j are two indices of the string. Define a 2-dimension array “table” and let table[i][j] denote whether a substring from i to j … Read more