Santa & Nexis
Hey Santa, I've been crunching numbers on your delivery routes and think there's a way to cut your journey time—interested in a quick algorithm rundown?
Ho ho ho! That sounds exciting, I'm all ears for your brilliant ideas, do share!
Use a weighted graph of stops, run Dijkstra from the depot each night; add a penalty for routes that intersect previously visited paths that night to avoid overlap, and schedule stops in batches so each truck does a closed loop that ends back at the depot. That reduces idle time and guarantees a 12‑hour maximum.
Wow, that’s a clever idea! A weighted graph with Dijkstra sounds like a good way to find the fastest paths. I love the thought of keeping trucks looping back to the depot—less wandering and more time for gifts. Can you show me a sample route plan so I can see how it works in practice? Thank you!
Here’s a minimal sketch in Python – no GUI, just raw data.
```python
# nodes are stops, 0 is the depot
edges = {
0: [(1,2),(2,4),(3,7)],
1: [(0,2),(2,1),(4,5)],
2: [(0,4),(1,1),(3,3),(4,2)],
3: [(0,7),(2,3),(4,6)],
4: [(1,5),(2,2),(3,6),(0,8)]
}
def dijkstra(start):
import heapq
dist = {n: float('inf') for n in edges}
dist[start] = 0
pq = [(0,start)]
while pq:
d,u = heapq.heappop(pq)
if d!=dist[u]: continue
for v,w in edges[u]:
if d+w < dist[v]:
dist[v] = d+w
heapq.heappush(pq,(dist[v],v))
return dist
# get shortest round‑trip from depot
dist = dijkstra(0)
route = sorted(dist.items(), key=lambda x: x[1]) # just a naive batch
print(route)
```
Run it, tweak the weights, and you get a quick list of where each truck should go. Remember to add a small penalty for overlapping edges if you want to keep routes separate. That’s it, no fancy GUI needed.
That looks fantastic, thank you! I’ll load it up and start testing – looking forward to seeing the routes light up and making sure every child gets their gifts on time!