High Graphs Question 178 of 224

How do you find the cheapest flights within at most k stops?

DSA interview set · Speak this in 60–90 seconds · Faridabad & Delhi NCR

PICTURE THIS: DATA SPLIT

Train 70%Val 15%Test 15%

Fit on train, tune on val, report on test once.

Simple meaning

Bellman-Ford style relaxation for k+1 rounds, or BFS/Dijkstra on a state (city, stops).

WHY — Graphs instead of guessing?

Why interviewers care about Graphs:

This is a process

question about Graphs.

Panels listen for order,

trade-offs, and what you would actually do on a DSA project - not buzzwords.

Stay structured

Name the idea, why it exists, then one short example.

Close cleanly

End with when you use it and one common pitfall.

STEPS — What happens with tokens?

Before the model can read a sentence, it goes through these steps:

1
Bellman-Ford style relaxation for
k+1 rounds, or BFS/Dijkstra on a state (city, stops).
2
Constrained Dijkstra is O(E
log V * k) depending on the heap key
3
k rounds of edge
relaxation are O(k * E).
4
Plain Dijkstra on city
only is wrong because a costlier path with fewer stops may win later.
5
Next token
The model scores what should come next.
6
Decode
IDs turn back into readable text.

EXAMPLE — See it in action

Here's a short line you can speak, broken into clear beats:

Say this line

“Constrained Dijkstra is O(E log V * k) depending on the heap key”

Break into beats

ConstrainedDijkstraisOElog

Speaking order

2987408337471632900

Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.

Key takeaway

Bellman-Ford style relaxation for k+1 rounds, or BFS/Dijkstra on a state (city, stops). Constrained Dijkstra is O(E log V * k) depending on the heap key