I applied online. The process took 3 days.

The Amazon interview consisted of three coding problems: two medium-level and one hard-level question, based on LeetCode difficulty. The coding questions primarily tested problem-solving ability, data structures and algorithms, code quality, and the ability to explain the approach clearly.

In addition to the technical round, there were several behavioral questions focused mainly on Amazon’s Leadership Principles. The interviewer asked for examples from past experiences to evaluate areas such as ownership, customer obsession, problem-solving, handling challenges, and delivering results. It was important to structure the answers using the STAR method (Situation, Task, Action, and Result) and provide specific examples with measurable outcomes where possible.

You are given an array routes representing bus routes where routes[i] is a bus route that the ith bus repeats forever.

For example, if routes[0] = [1, 5, 7], this means that the 0th bus travels in the sequence 1 -> 5 -> 7 -> 1 -> 5 -> 7 -> 1 -> ... forever.

You will start at the bus stop source (You are not on any bus initially), and you want to go to the bus stop target. You can travel between bus stops by buses only.

Return the least number of buses you must take to travel from source to target. Return -1 if it is not possible.