Amazon Interview | Set 15
For the position SDE I.
I had an online test through interviewstreet and following were the questions:
- Inorder Successor in BST
- K distance from root
- Clone a linked list with next and random pointer
F2F Interview :
1. Generate all valid permutations using ‘(‘ and ‘)’. Valid permutation is the general definition of valid sequence of the opening and closing brackets.
I told him a solution where we would generate a combination using a recursive solution and prune the cases where a valid combination is no longer possible. The solution was fine and not that difficult. But the interviewer was very interested in knowing if I can calculate the complexity of the solution. He gave me some hints but it was just not striking me. I told him my approximate answer. We moved on.
2. Create an ancestor matrix for a tree.
The solution would seem simple. But since the matrix is N*N, the interviewer wanted some tricks to reduce the complexity of the write operation on the matrix.
I told him a solution where you can initialize the matrix with all zeros and only write 1 for the ancestor cell using a modifies recursive solution and linkedlist.
He was fine with the solution
F2F 2:
1. Find the maximum weight node in a tree if each node is the sum of the weights all the nodes under it. Obviously tree nodes can have negative weights.
2. Kadane’s algo
F2F 3:
1. Find the diameter of a tree.
2. Link every node of a level to the next node at the same level
eg:
Tree is:
1
2 3
4 5 6 7
would become:
1
2-->3
4--->5--->6--->7
3. Find the first subarray which has a zero sum in an array
F2F 4:
Detailed discussion on projects I did in college and about my interests.
This article is compiled by girlforce.
Last Updated :
19 Aug, 2019
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