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PODiGraph: Nearest node that joins all paths
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Id
19933364
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0
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CreationDate
2013-11-12T15:36:25.390
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2013-11-12T19:33:12.027
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286
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text
Body
<h3>Some background</h3> I'm analyzing the control flow graph of a function which basically maps incoming data onto outgoing data. Most of the blocks are like this one: <pre class="lang-c prettyprint-override"><code>if (input_variable == SPECIFIC_CONSTANT) { output_variable = TRUE; } else { output_variable = FALSE; } </code></pre> Typical Control Flow Graph for such code looks like the following graph <pre><code>digraph G { 2 -> 3 -> 5; 2 -> 4 -> 5; } </code></pre> <a href="http://i.imgur.com/q7Pu2ja.png">Picture of the graphe</a> where execution of <code>3</code> and <code>4</code> are conditioned by the value of the <code>input_variable</code> but <code>5</code> is independent. <h3>The question</h3> Given a directed graph and a start node, how do I find the nearest node such that any path from the start node goes through this node? Example: Given <a href="http://i.imgur.com/gjLVlQX">this graph</a> how do I find <code>6</code> starting from <code>2</code> or <code>12</code> starting from <code>8</code>? Can I reverse a Lowest Common Ancestor algorithm and would it be efficient? Like <pre><code>for each node in graph: ancestors = node.get_all_ancestors() lca = find_lowest_common_ancestor(ancestors) junction_node[lca] = node get_junction_point(node): return junction_node[node] </code></pre> My programming language is Python and I just discovered NetworkX, but any algorithm would be appreciated. I am not accustomed to graph theory and I think I miss the basic glossary to find what I'm looking for. Thanks for your help!
Tags
<python><algorithm><graph>
Title
DiGraph: Nearest node that joins all paths
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1. This table or related slice is empty.
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1. This table or related slice is empty.
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1. PTQuestion
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1. USCilyan
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