25 lines
993 B
Matlab
25 lines
993 B
Matlab
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% Find the stronly connected components in a directed graph
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% Source: Tarjan, R. E. (1972), "Depth-first search and linear graph algorithms",
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% SIAM Journal on Computing 1 (2): 146-160
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% Wikipedia description: http://en.wikipedia.org/wiki/Tarjan's_strongly_connected_components_algorithm
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%
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% Input: graph, set of nodes and edges, in adjacency list format,
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% example: L{1}=[2], L{2]=[1] is a single (1,2) edge
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% Outputs: set of strongly connected components, in cell array format
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%
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% Other routines used: strongConnComp.m
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% GB: last updated, Sep 22, 2012
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function [GSCC,v] = tarjan(L)
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GSCC = {};
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ind = 1; % node number counter
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S = []; % An empty stack of nodes
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for ll=1:length(L); v(ll).index = []; v(ll).lowlink = []; end % initialize indices
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for vi=1:length(L)
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if isempty(v(vi).index)
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[GSCC,S,ind,v]=strongConnComp(vi,S,ind,v,L,GSCC); % visit new nodes only
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end
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end
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