Amazon Software Development Engineer interview questions

1st round written 20 questions,18 mcqs and 2 programs

Round1 : Telephonic Interview 1) Given a Binary Search Tree, Find out the distance between two Given Nodes 2) Solve the previous problem for Binary Tree Round2 : Written Test 1) Given a Binary Tree, set sibling pointer for each node. (Assume that sibling pointer exists in the node) 2) Given a Binary Tree and a number n, check whether there exists a path from root to some leaf such that sum of all values in that nodes it path equals n. 3) Given a array of characters of this replace the characters which occur continously with the character and no. of times it occured e.g. AAAABCCDDD A4BC3D3 (count for characters that occurs once can be ignored) Round3: Technical Interview 1) Given a Binary Tree, Find out the all vertical sums from root to all leaves. 2) In a Binary Tree, Each node has an additional pointer which points to either NULL or inorder successor of that node or garbage pointer. Write a function to set all the garbage pointers to NULL. Round4: Technical Interview 1) Given two prime numbers n1, n2 find out the minimum no. of operations required to change n1 to n2. The only allowed operation is we can change 1 digit can be interchanged with an additional constraint that the intermediate no. must also be prime. Round5: Technical Interview 1) Simple questions regarding Operating systems Round6: Telephonic Interview 1) Give an O(n) solution for Maximum Subarray problem? 2) An unbounded byte array contains characters. Each character is 1 or 2 byte long. There are no delimiters between characters. The MSB of 1-byte character would be 0. The MSB of left byte of 2 byte characater would be 1 and MSB of right byte (second) can be either 0 or 1