floodfill

n people, n jobs, each person has skills corresponding to specific jobs

Dungeons and Dragons

direct

Key components or principles of other algorithms

Traverse connected components using adjacency sets

Find connected components

The problem of the Seven Bridges of Königsberg

"Traveling the World" Question

no inner wall

Can lay a continuous wallpaper

Each barrier has exactly one connection point with the exterior wall

Discover all points and follow all paths twice (one direction each time)

Code

Mark every entry/exit intersection

If possible, avoid crossing intersections that have already been visited and avoid taking paths that have already been traveled

Iterate

Universal

Consider it in terms of an undirected graph

time of discovery

Backtracking time passed

DFS with timestamp

DFS-based topological sorting

Each node is found before the descendants of the DFS tree

Each node is completed after the descendants of the DFS tree

Ch4

Notice

Traversal order

Node colors and edge types

Detour

If it starts at intersection a

First visit all intersections with a path, and return to the starting point each time

If it's a dead end, mark it closed after returning

Every intersection that takes you to a closed point is also marked closed

through an open passage

Now there are two markers on it

Assume it is point b, traverse all open paths of b

After completion, return to a and proceed to the next opening of a until all are two marks

All open paths starting from a now have n-1 markers

Remove all neighbors of a and mark until all n-1

Nodes and edges will be traversed multiple times, and the worst case reaches square

Trees generally have many nodes at the bottom and can be close to linear

Add additional logging information

Maintain a distance table

A distance dictionary and a parent node dictionary to facilitate finding the shortest path

Search a huge tree

Python lists

bidirectional list deque

Vertices u and v can reach each other

Every two vertices of the directed graph G are strongly connected.

Maximum strongly connected subgraph of non-strongly connected graph

goal oriented

pruning

A* algorithm

branch and bound

by Cormen et al