Network Delay Time (Djikstra's Algorithm) - Leetcode 743 - Graphs (Python)

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[GregHogg]

Master Data Structures & Algorithms For FREE at AlgoMap.io!

[shxdow]

two things i did differently in my implementation. 1. I used a visited set and didn't need the min times dict. You can just store the max time any time a new node is added to the visited set. Since we are using a heap, we are guaranteed that the node popped off the heap first, if it is not visited, is the lowest cost unvisited node. 2. You don't need to check whether the neighbors are in min times, since if they were, you are anyway skipping those nodes with the earlier if condition. So that second check would be redundant.

[jmgpqcx]

heapq is doing a lot of heavy lifting for us here

[mehraan]

Should we not update the cost to reach a node even if it is already in min_times because a different path may give a lesser cost/time? Please help.

[aakashs]

Can we solve this problem in prims algorithm??

[chisomedoka]

Great video once again, please create one for BellmanFord

[Dcebox]

is ther eany similarity between the min heap in dijkstras, and the min heap used in prims mst algo?

[hyrax_attack]

Not your best explanation Greg, thanks a lot still :)

[otheraccount]

Heapq.heapify(min_heap) missing in code.