Amazon Interview Experience | Set 245 (For 2.5 Years Experienced)

Round 1:
Q-1 Given an array os 0s and 1s, and another input m, I was supposed to tell the longest continuous streak of 1s after flipping m 0s to 1s. E.g., Array is {1,1,0,0,1,1,1,0,1,1} m = 1 (which means I can flip ‘m’ one 0 to 1)
Answer: 6 (if we flip 0 at index 7, we get the longest continuous streak of 1s having length 6)

Q-2 Given N ropes of lengths L1, L2, L3, L4, …, LN. I had to join every rope to get a final rope of length L1 + L2 + … + LN.
However, I can join only two ropes at a time and the cost of joining the two ropes is L1 + L2. I was supposed to join ropes in such a way that the cost is minimum.

Round 2:
Q-3 Given a BST, I needed to serialize it and deserialize it. This essentially boiled down to generating the “traversal” string and getting the BST back from the traversal.

Q-4 There are two linked lists. Both linked lists have a single-digit number in their nodes. I needed to
treat this linked lists as a numbers and add them up and store the digits in a new linked list.
E.g., head -> 5 -> 6 -> 7-> 9
head -> 2-> 1 -> 1
Resultant linked list: head-> 5 -> 8-> 9-> 0 (5679 + 211 = 5890)

Round 3: Hiring Manager round
Q-5 Project discussion in detail. Most challenging problem, how did you solve it, had any disagreement with manager, how did you fix it etc.
Q-6 Given an array {2, 4, 6, 0, 1, 8, 1}, where each element represents the height of tower located at its index. I was supposed to tell how much maximum water can accumulate in this “valley” once it rains.

Round 4:
Q-7 Given the encoding rule:
A -> 0
B -> 1
C -> 2

K -> 10

Z -> 25
I was supposed to get the number of original strings possible given an encoded input.
E.g., Given input 10, two possible original strings are possible BA and K, the answer is 2.

Q-8 Given two trees, find out if the second tree is a “subtree” of the first one.

E.g., Tree 1
       /   \
      B     C   
    /  \     \
   D    E     F 

Tree 2:
   /   \
  D     E

Answer: Yes (B is a subtree of A)
Tree 2:
   /   \
  D     E

Answer: No (Tree 2 is not a subtree of Tree A)

Round 5: Engineering manager round
Q-8 Engineering Manager round, all behavioral, why do you want to leave the company, one challenging problem, how did you overcome it, your biggest failure etc. etc.

If you like GeeksforGeeks and would like to contribute, you can also write an article and mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks.

Write your Interview Experience or mail it to

My Personal Notes arrow_drop_up

Article Tags :
Practice Tags :

Be the First to upvote.

Please write to us at to report any issue with the above content.