Amazon SDE Interview Questions, Process, and Tips

A tree is a data structure consisting of nodes connected by edges, with a single root node and no cycles.

• Nodes represent elements of the tree, and edges represent the relationships between them.

• Each node can have zero or more child nodes, and each child node can have its own children.

• Trees are commonly used in computer science for organizing and searching data, such as in binary search trees.

• Examples of trees include f...read more

Graphs are non-linear data structures with cycles while trees are hierarchical data structures without cycles.

• Graphs can have cycles while trees cannot

• Graphs can have multiple root nodes while trees have only one

• Graphs can have disconnected components while trees are always connected

• Graphs can have directed or undirected edges while trees have only directed edges

• Examples of graphs include social networks, road networks...read more

A graph can be called a tree if it is connected and has no cycles.

• A tree is a type of graph with no cycles.

• It must be connected, meaning there is a path between any two vertices.

• It has n-1 edges, where n is the number of vertices.

• Examples include family trees, file directory structures, and decision trees.

Program to determine if a graph is a tree using adjacency matrix

• A graph is a tree if it is connected and has no cycles

• Check if the graph is connected by performing a depth-first search or breadth-first search

• Check if the graph has cycles by performing a depth-first search and tracking visited nodes

Seeking better growth opportunities and a more challenging role.

• Limited growth opportunities in my current company

• Looking for a more challenging role to enhance my skills

• Seeking a company with a better work culture and values

• Exploring options that align better with my long-term career goals

A thread is a unit of execution within a process that can run independently and concurrently with other threads.

• Threads allow for concurrent execution of tasks within a program.

• Threads share the same memory space and resources of the process they belong to.

• Threads can communicate and synchronize with each other through shared data structures like locks and semaphores.

• Threads can improve performance by utilizing multipl...read more

Memory leakage is a situation where a program fails to release memory it no longer needs.

• Memory leakage can cause a program to slow down or crash due to insufficient memory.

• It is caused by programming errors such as not freeing allocated memory or losing references to it.

• Examples include forgetting to close a file or database connection, or not releasing memory allocated for a variable.

• Memory leakage can be detected us...read more

Design a system using Max Heap to find the costliest element from a box when an element is picked.

• Implement a Max Heap data structure to store the elements in the box.

• Whenever an element is picked, the costliest element can be found at the root of the Max Heap.

• After picking an element, update the Max Heap by removing the root and reorganizing the heap.

• Ensure the Max Heap property is maintained during insertion and dele...read more

LRU cache is a data structure that stores most recently used items and discards least recently used items.

• LRU stands for Least Recently Used

• It is implemented using a doubly linked list and a hash map

• When an item is accessed, it is moved to the front of the list

• When the cache is full, the least recently used item is removed from the end of the list

• Example: A web browser cache that stores recently visited web pages