Start-End Pair Generation | Dataford Interview Questions

Provided the list of connected nodes, how would you get the list of all available Start, End pairs?

Implement all_start_end_pairs(graph). The input is a dictionary mapping each node to its directly connected nodes, and nodes may appear only as neighbors. Return every distinct ordered [start, end] pair where end is reachable from start, excluding pairs with identical nodes, sorted lexicographically.

Signature: all_start_end_pairs(graph)

Example: {"A": ["B"], "B": ["C"], "C": []} returns [["A", "B"], ["A", "C"], ["B", "C"]].

Constraints: Node labels are strings, edges form a finite directed graph, and duplicate connections may appear.

Constraints

Node labels are strings.
The graph is directed.
The graph contains a finite number of nodes and edges.
Duplicate connections may appear.
Pairs must be unique, ordered, and exclude start == end.

Function Signature

def all_start_end_pairs(graph):

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