Switching to segtree based Dijkstra for extra speed#55
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bjorn-martinsson wants to merge 1 commit intocheran-senthil:masterfrom
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Switching to segtree based Dijkstra for extra speed#55bjorn-martinsson wants to merge 1 commit intocheran-senthil:masterfrom
bjorn-martinsson wants to merge 1 commit intocheran-senthil:masterfrom
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cheran-senthil
approved these changes
Jan 23, 2021
| @@ -1,18 +1,50 @@ | |||
| from heapq import heappop, heappush | |||
| inf = -1 | |||
Owner
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Think maybe having a comment here would be nice
Comment on lines
+36
to
+37
| def dijkstra(self, graph, start): | ||
| n = len(graph) |
Owner
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Some small docstring would be nice
| D = DistanceKeeper(n) | ||
| D[start] = 0 | ||
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| for node in Dseg.trav(): |
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Python has a problem with being slow when it comes to having tuples inside of a heap. There have been multiple problems on codeforces.com with currently no accepted python heap Dijkstra solutions. This PR adds a much more optimized Dijkstra using segment trees to get around using tuples and heaps.