Robina Li

Given a string s, return the longest palindromic substring in s.

Given an n-ary tree, return the level order traversal of its nodes’ values.

You have a graph of n nodes labeled from 0 to n - 1. You are given an integer n and an array edges where edges[i] = [ai, bi] indicates...

Given the root of a binary tree, return the level order traversal of its nodes’ values. (i.e., from left to right, level by level).

Given the root of a binary tree with unique values and the values of two different nodes of the tree x and y, return true if the nodes corresponding to...

Given the root of a binary tree, return the zigzag level order traversal of its nodes’ values. (i.e., from left to right, then right to left for the next level...

Given an integer array nums and an integer k, return the kth largest element in the array.

Welcome to the Heap templates page! Here you’ll find battle-tested Python snippets for every common heap (priority queue) pattern on LeetCode — from basic min/max heaps to advanced techniques like...

Given an integer array nums, find the subarray with the largest sum, and return its sum.

A wiggle sequence is a sequence where the differences between successive numbers strictly alternate between positive and negative. The first difference (if one exists) may be either positive or negative....