Commonly asked Technical Interview Questions at Amazon:

  • Given an input stream of strings, find the most frequent string.
  • Find the longest palindromic substring.
  • Copy a LinkedList with Random Pointers.
  • Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.)
  • Given a sorted array of integers in increasing order (can contain duplicates), return the last index of a specified target integer, or return -1 otherwise.
  • How to shuffle a deck of cards?
  • Determine if a 9x9 Sudoku board is valid.
  • Given an input string, reverse the string word by word.
  • Construct a binary tree from a string consisting of parenthesis and integers.
  • Return the k-closest points to the center of a cartesian plane given an array of coordinates.
  • Write a function that rotates a 2-dimensional array clockwise or counterclockwise 90 degrees depending on a given parameter.
  • Given a non-negative integer num represented as a string, remove k digits from the number so that the new number is the smallest possible.
  • Finding the intersection of two lists of strings.
  • Given a list of weighted edges between nodes, find the minimum cost spanning tree.
  • List down the paths in a binary tree that sum up to the given sum.
  • Sort out the top K frequently used words by users.  
  • Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, add spaces in s to construct a sentence where each word is a valid dictionary word. Return all such possible sentences.
  • Given an array of meeting time intervals consisting of start and end times, find the minimum number of conference rooms required.
  • Given a string, determine if a permutation of the string could form a palindrome.
  • Given a binary tree, find the length of the longest consecutive sequence path.

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