Challenge: Trace the Complete Path of a Journey

Problem Statement #

You have to implement the trace_path() function which will take in a list of source-destination pairs and return the correct sequence of the whole journey from the first city to the last.

Input #

A Python dict containing string pairs of source-destination cities.

Output #

A list of source-destination pairs in the correct order.

Sample Input #

dict = {
  "NewYork": "Chicago",
  "Boston": "Texas",
  "Missouri": "NewYork",
  "Texas": "Missouri"
}

Sample Output #

[["Boston", "Texas"] , ["Texas", "Missouri"] , ["Missouri", "NewYork"] , ["NewYork", "Chicago"]]