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

1) Write functions to serialize and deserialize a tree. 2) Determine if two numbers in the list sum to a target number.

1) Write a stack class that keeps track of the minimum value in the stack. 2) Given n non-negative integers a1, a2, ..., an , where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of the line i is at (i, ai) and (i, 0). Find two lines, which, together with the x-axis forms a container, such that the container contains the most water.

1) Given a list of JSON objects containing years of birth and death for a given person, return the year in which the most people are alive.

Find the minimum price to paint all houses given a price list for each house and colors.

1) Given a binary tree where every node has either 0 or 2 children and every right node is a leaf node, flip it upside down turning it into a binary tree where all left nodes are leafs. 2) Find all palindromic decompositions of a given string s. A palindromic decomposition of string is a decomposition of the string into substrings, such that all those substrings are valid palindromes.

1) Write an XML parser. 2) Write an XML formatter.

Determine if a graph is bipartite

Given an input string such as 'a2b3c4' produce an output string like 'aaabbbbccccc'

1) Given a integer as a input, replace all the ‘0’ with ‘5’ in the integer. 2) You are crossing a river using a series of rocks that stick out from the water. You can move across either one-rock at a time, or jump a rock in order to move ahead two rocks. Given there are 'r' rocks, how many distinct ways, 'n', can you cross? 3) Write an efficient program for printing k largest elements in an array. Largest elements are returned in order largest to smallest.

Given two strings s1 and s2, write a function to return true if s2 contains the permutation of s1. In other words, one of the first string's permutations is the substring of the second string.

Return the node that begins the intersection of two linked lists.

Given two strings s1 and s2, write a function to return true if s2 contains the permutation of s1. In other words, one of the first string permutations is the substring of the second string.

1) Design an LRU cache. 2) Find the longest common prefix from an array of strings.

Given an array of characters and a string, implement a function that finds the smallest substring containing all the characters in the array.

1) Given two linked lists, merge them into one such that their values are in sorted order. 2) Given a full binary tree, return an array containing the boundary elements from the left, then bottom, then right side, without duplicates.

Given a 2D matrix, where 1 represents land and 0 represents water, count how many islands are present

Given a list of numbers representing the time to sleep, write a function to output the order when each thread sleeps for the given amount of time.

1) Given two strings, is one of the strings a rotated version of the other? 2) Given an array of numbers containing pairs of numbers, except for one single number, find the single number within the array. 3) Given a dollar amount and a list of denominations, find the count of the optimal way to make change.

1) Write a function that checks if a string is a strict palindrome. 2) Write a function that checks if a string is a palindromic phrase. That is, it ignores non-alphabetic characters and ignores case. 3) Write a function that deep copies a linked list, where each node contains data and a pointer to a different node. 4) Print a linked list in reverse order.

1) Reverse the order of the words in a string 2) Modify part 1 such that the punctuation stays in place while the words are reversed.

1) Check whether it is possible to partition an array. 2) Is there a way to get from one city to the other with the given bus routes?

Given a list of integers L, find the maximum length of a sequence of consecutive numbers that can be formed using elements from L.

1) Given a dictionary of words, determine whether it is possible to transform a given word into another with a fixed number of characters 2) Modify the approach so that transitions between varying quantities were possible 3) Modify the code to work as an API with lots of words added to the dictionary, but few tests 4) Determine the largest sum of a contiguous subarray

If it is possible, return any [i, j], such that * Z[0], Z[1], ..., Z[i] is the first part; * Z[i+1], Z[i+2], ..., Z[j-1] is the second part, and * Z[j], Z[j+1], ..., Z[Z.length - 1] is the third part. * All three parts have equal binary value.

Find pairs of values that sum up to a given value.

1) Given a list of points as [x,y] pairs; a vertex in [x,y] form; and an integer k, return the kth closest points in terms of Euclidean distance 2) Assuming that the dataset is too big to store in memory, rewrite functions for distributed system

Derive the order of the letters given a list of words

1) Given a value, return the optimal number of coins [1,5,10,25] to make the value. 2) Given a value and a set of coins, return the optimal count of coins to achieve the value

1) Write a function that takes a string as an input and returns a shuffled version of that string (i.e. a version where each character is just as likely to be in any given position) 2) Write a function that analyzes how well your previous function randomly shuffles the string

1) Given two strings s1 and s2, write a function that returns if the two strings are equal in a case-insensitive way 2) Expand the first function such that it returns True if the edit distance between s1 and s2 is 1 or lower 3) Expand the function to take a third parameter designating the comparision tolerance between s1 and s2 to be 'n' edit distances or lower

1) Write a function to reverse a given string 2) Given an unsorted array of unique integers (size n + 1) and a second array that is identical to the first array but missing one integer (size n), find and output the missing integer

Given an integer array and number k, output all unique pairs that sum up to k. Example: for input [1, 3, 2, 5, 46, 6, 7, 4] and k = 4, output (1, 3).