Difference between revisions of "TADM2E 6.21"

Revision as of 01:42, 14 July 2020

China get out

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-Step 1:
+China get out
-Perform topological sorting of the graph (we can do it as Graph is acyclic). This is O(n + m)
-Step 2:
-Go through vertices in topological order. Initially all vertices marked as inaccessible and only starting vertex marked with 0 distance.
-For every vertex in cycle, if it is accessible, we update all its children with new distance if new distance is shorter then previous one.
-Topological sorting ensures that we don't ever need to go backtrack. This is O(n + m).
-Total running bound is O(n+m), which is linear as requested.