Amazon Mobile Engineer Coding Questions

Amazon Prime needs to calculate the shortest delivery route between multiple distribution centers and customer locations, considering shipping times based on real-time traffic data represented in the form of a graph.Given the number of nodes, a list of edges where each edge has a start node, an end node, and a weight (time cost), and a starting_node, implement a function that returns the shortest path to each node from the starting_node.Input: int nodes, List[Tuple[int, int, int]] edges, int starting_node
Output: Dict[int, int] - mapping from node to shortest time cost.Example 1:
Input: 5, [(0, 1, 10), (0, 2, 5), (1, 2, 2), (1, 3, 1), (2, 1, 3), (2, 3, 9), (2, 4, 2), (3, 4, 4)], starting_node = 0
Output: {0: 0, 1: 7, 2: 5, 3: 8, 4: 10}
Explanation: The shortest path from node 0 to all other nodes is calculated using Dijkstra's algorithm.Example 2:
Input: 3, [(0, 1, 2), (0, 2, 1), (1, 2, 4)], starting_node = 0
Output: {0: 0, 1: 2, 2: 1}
Explanation: The shortest path from node 0 leads directly to nodes 1 and 2.Constraints:
- 1 <= nodes <= 10^5
- 1 <= edges.length <= 2 * 10^5
- 0 <= edges[i][0], edges[i][1] < nodes
- 1 <= edges[i][2] <= 10^5

In order to improve user experience and prevent notification overload, Amazon needs a solution that efficiently aggregates notifications sent to users in a sliding time window.Given a list of notifications represented as timestamps and a maximum allowed number of notifications within a defined time_window, implement a function to return the count of unique notifications that should be shown to users.Input: List[int] notifications, int time_window
Output: int - the count of unique notifications to be displayed.Example 1:
Input: [1, 2, 3, 4, 1, 2, 3], time_window = 5
Output: 4
Explanation: Notifications 1, 2, 3, 4 are shown within a 5-second window.Example 2:
Input: [1, 1, 2, 2, 2, 3, 3], time_window = 3
Output: 3
Explanation: Notifications 1, 2, 3 are shown within a 3-second window.Constraints:
- 1 <= notifications.length <= 10^5
- 0 <= notifications[i] <= 10^9
- 1 <= time_window <= 10^5