Programming Interview questions

programming_interview_questions.md

#General Find the most frequent integer in an array Find pairs in an integer array whose sum is equal to 10 (bonus: do it in linear time) Given 2 integer arrays, determine of the 2nd array is a rotated version of the 1st array. Ex. Original Array A={1,2,3,5,6,7,8} Rotated Array B={5,6,7,8,1,2,3} Write fibbonaci iteratively and recursively (bonus: use dynamic programming) Find the only element in an array that only occurs once. Find the common elements of 2 int arrays Implement binary search of a sorted array of integers Implement binary search in a rotated array (ex. {5,6,7,8,1,2,3}) Use dynamic programming to find the first X prime numbers Write a function that prints out the binary form of an int Implement parseInt Implement squareroot function Implement an exponent function (bonus: now try in log(n) time) Write a multiply function that multiples 2 integers without using * HARD: Given a function rand5() that returns a random int between 0 and 5, implement rand7() HARD: Given a 2D array of 1s and 0s, count the number of "islands of 1s" (e.g. groups of connecting 1s) Strings Find the first non-repeated character in a String Reverse a String iteratively and recursively Determine if 2 Strings are anagrams Check if String is a palindrome Check if a String is composed of all unique characters Determine if a String is an int or a double HARD: Find the shortest palindrome in a String HARD: Print all permutations of a String HARD: Given a single-line text String and a maximum width value, write the function 'String justify(String text, int maxWidth)' that formats the input text using full-justification, i.e., extra spaces on each line are equally distributed between the words; the first word on each line is flushed left and the last word on each line is flushed right Trees Implement a BST with insert and delete functions Print a tree using BFS and DFS Write a function that determines if a tree is a BST Find the smallest element in a BST Find the 2nd largest number in a BST Given a binary tree which is a sum tree (child nodes add to parent), write an algorithm to determine whether the tree is a valid sum tree Find the distance between 2 nodes in a BST and a normal binary tree Print the coordinates of every node in a binary tree, where root is 0,0 Print a tree by levels Given a binary tree which is a sum tree, write an algorithm to determine whether the tree is a valid sum tree Given a tree, verify that it contains a subtree. HARD: Find the max distance between 2 nodes in a BST. HARD: Construct a BST given the pre-order and in-order traversal Strings Stacks, Queues, and Heaps Implement a stack with push and pop functions Implement a queue with queue and dequeue functions Find the minimum element in a stack in O(1) time Write a function that sorts a stack (bonus: sort the stack in place without extra memory) Implement a binary min heap. Turn it into a binary max heap HARD: Implement a queue using 2 stacks Linked Lists Implement a linked list (with insert and delete functions) Find the Nth element in a linked list Remove the Nth element of a linked list Check if a linked list has cycles Given a circular linked list, find the node at the beginning of the loop. Example: A-->B-->C --> D-->E -->C, C is the node that begins the loop Check whether a link list is a palindrome Reverse a linked list iteratively and recursively Sorting Implement bubble sort Implement selection sort Implement insertion sort Implement merge sort Implement quick sort