### [Programming Problem] Number of Pairs of Strings With Concatenation Equal to Target

[Problem Link] Given an array of digit strings nums and a digit string target, return the number of pairs of indices (i, j) (where...

### [Programming Problem] Subsets II

Given an integer array nums that may contain duplicates, return all possible subsets (the power set). The solution set must not contain duplicate subsets....

### [Programming Problem] Flatten Binary Tree to Linked List

Given the root of a binary tree, flatten the tree into a “linked list”: – The “linked list” should use the same TreeNode class...

### [Programming Problem] Largest Number

Given a list of non-negative integers nums, arrange them such that they form the largest number and return it.   Since the result may...

### [Programming Problem] Sum Root to Leaf Numbers

You are given the root of a binary tree containing digits from 0 to 9 only.   Each root-to-leaf path in the tree represents...

### [Programming Problem] Reverse Linked List II

Given the head of a singly linked list and two integers left and right where left <= right, reverse the nodes of the list...

### [Programming Problem] Jump Game II

Given an array of non-negative integers nums, you are initially positioned at the first index of the array. Each element in the array represents...

### [Programming Problem] Find Minimum in Rotated Sorted Array II

Suppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums = [0,1,4,4,5,6,7]...

### [Programming Problem] Find Minimum in Rotated Sorted Array

Suppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums = [0,1,2,4,5,6,7]...

### [Programming Problem] Print FooBar Alternately

Suppose you are given the following code: class FooBar { public void foo() { for (int i = 0; i < n; i++) {...