How should I practice Cheapest Flights Within K Stops?

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Cheapest Flights Within K Stops

Amazon● MediumFULLTIMEPHONE SCREENONSITE INTERVIEW

Problem statement

There are n cities numbered from 0 to n - 1. You are given an array flights where flights[i] = [from_i, to_i, price_i] means there is a directed flight from city from_i to city to_i with cost price_i.

You are also given integers src, dst, and k. Return the cheapest price from src to dst with at most k stops. If no such route exists, return -1.

Function

findCheapestPrice(n: int, flights: int[][], src: int, dst: int, k: int) → int

Examples

Example 1

n = 4flights = [[0,1,100],[1,2,100],[2,0,100],[1,3,600],[2,3,200]]src = 0dst = 3k = 1return = 700

The route 0 -> 1 -> 3 costs 700 and uses 1 stop. The cheaper route 0 -> 1 -> 2 -> 3 costs 400 but uses 2 stops, which exceeds k.

Example 2

n = 3flights = [[0,1,100],[1,2,100],[0,2,500]]src = 0dst = 2k = 1return = 200

The route 0 -> 1 -> 2 costs 200 with 1 stop, which is cheaper than the direct flight of 500.

Constraints

1 <= n <= 100.
0 <= flights.length <= n * (n - 1).
flights[i].length == 3.
0 <= from_i, to_i < n.
from_i != to_i.
1 <= price_i <= 10^4.
There are no duplicate flights and no self-flights.
0 <= src, dst, k < n.
src != dst.