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<h1 class='fqn'><span class='in-band'>Function <a href='../index.html'>petgraph</a>::<wbr><a href='index.html'>algo</a>::<wbr><a class="fn" href=''>astar</a></span><span class='out-of-band'><span id='render-detail'>
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</span><a class='srclink' href='../../src/petgraph/astar.rs.html#67-133' title='goto source code'>[src]</a></span></h1>
<pre class='rust fn'>pub fn astar&lt;G, F, H, K, IsGoal&gt;(<br>&nbsp;&nbsp;&nbsp;&nbsp;graph: G, <br>&nbsp;&nbsp;&nbsp;&nbsp;start: G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>, <br>&nbsp;&nbsp;&nbsp;&nbsp;is_goal: IsGoal, <br>&nbsp;&nbsp;&nbsp;&nbsp;edge_cost: F, <br>&nbsp;&nbsp;&nbsp;&nbsp;estimate_cost: H<br>) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.tuple.html">(</a>K, <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/vec/struct.Vec.html" title="struct alloc::vec::Vec">Vec</a>&lt;G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>&gt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.tuple.html">)</a>&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;G: <a class="trait" href="../../petgraph/visit/trait.IntoEdges.html" title="trait petgraph::visit::IntoEdges">IntoEdges</a> + <a class="trait" href="../../petgraph/visit/trait.Visitable.html" title="trait petgraph::visit::Visitable">Visitable</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;IsGoal: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnMut.html" title="trait core::ops::function::FnMut">FnMut</a>(G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>: <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.Eq.html" title="trait core::cmp::Eq">Eq</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/hash/trait.Hash.html" title="trait core::hash::Hash">Hash</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnMut.html" title="trait core::ops::function::FnMut">FnMut</a>(G::<a class="type" href="../../petgraph/visit/trait.IntoEdgeReferences.html#associatedtype.EdgeRef" title="type petgraph::visit::IntoEdgeReferences::EdgeRef">EdgeRef</a>) -&gt; K,<br>&nbsp;&nbsp;&nbsp;&nbsp;H: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnMut.html" title="trait core::ops::function::FnMut">FnMut</a>(G::<a class="type" href="../../petgraph/visit/trait.GraphBase.html#associatedtype.NodeId" title="type petgraph::visit::GraphBase::NodeId">NodeId</a>) -&gt; K,<br>&nbsp;&nbsp;&nbsp;&nbsp;K: <a class="trait" href="../../petgraph/algo/trait.Measure.html" title="trait petgraph::algo::Measure">Measure</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Copy.html" title="trait core::marker::Copy">Copy</a>,&nbsp;</span></pre><div class='docblock'><p>[Generic] A* shortest path algorithm.</p>
<p>Computes the shortest path from <code>start</code> to <code>finish</code>, including the total path cost.</p>
<p><code>finish</code> is implicitly given via the <code>is_goal</code> callback, which should return <code>true</code> if the
given node is the finish node.</p>
<p>The function <code>edge_cost</code> should return the cost for a particular edge. Edge costs must be
non-negative.</p>
<p>The function <code>estimate_cost</code> should return the estimated cost to the finish for a particular
node. For the algorithm to find the actual shortest path, it should be admissible, meaning that
it should never overestimate the actual cost to get to the nearest goal node. Estimate costs
must also be non-negative.</p>
<p>The graph should be <code>Visitable</code> and implement <code>IntoEdges</code>.</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">petgraph</span>::<span class="ident">Graph</span>;
<span class="kw">use</span> <span class="ident">petgraph</span>::<span class="ident">algo</span>::<span class="ident">astar</span>;
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">g</span> <span class="op">=</span> <span class="ident">Graph</span>::<span class="ident">new</span>();
<span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">0.</span>, <span class="number">0.</span>));
<span class="kw">let</span> <span class="ident">b</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">2.</span>, <span class="number">0.</span>));
<span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">1.</span>, <span class="number">1.</span>));
<span class="kw">let</span> <span class="ident">d</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">0.</span>, <span class="number">2.</span>));
<span class="kw">let</span> <span class="ident">e</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">3.</span>, <span class="number">3.</span>));
<span class="kw">let</span> <span class="ident">f</span> <span class="op">=</span> <span class="ident">g</span>.<span class="ident">add_node</span>((<span class="number">4.</span>, <span class="number">2.</span>));
<span class="ident">g</span>.<span class="ident">extend_with_edges</span>(<span class="kw-2">&amp;</span>[
(<span class="ident">a</span>, <span class="ident">b</span>, <span class="number">2</span>),
(<span class="ident">a</span>, <span class="ident">d</span>, <span class="number">4</span>),
(<span class="ident">b</span>, <span class="ident">c</span>, <span class="number">1</span>),
(<span class="ident">b</span>, <span class="ident">f</span>, <span class="number">7</span>),
(<span class="ident">c</span>, <span class="ident">e</span>, <span class="number">5</span>),
(<span class="ident">e</span>, <span class="ident">f</span>, <span class="number">1</span>),
(<span class="ident">d</span>, <span class="ident">e</span>, <span class="number">1</span>),
]);
<span class="kw">let</span> <span class="ident">path</span> <span class="op">=</span> <span class="ident">astar</span>(<span class="kw-2">&amp;</span><span class="ident">g</span>, <span class="ident">a</span>, <span class="op">|</span><span class="ident">finish</span><span class="op">|</span> <span class="ident">finish</span> <span class="op">==</span> <span class="ident">f</span>, <span class="op">|</span><span class="ident">e</span><span class="op">|</span> <span class="kw-2">*</span><span class="ident">e</span>.<span class="ident">weight</span>(), <span class="op">|</span>_<span class="op">|</span> <span class="number">0</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">path</span>, <span class="prelude-val">Some</span>((<span class="number">6</span>, <span class="macro">vec</span><span class="macro">!</span>[<span class="ident">a</span>, <span class="ident">d</span>, <span class="ident">e</span>, <span class="ident">f</span>])));</pre>
<p>Returns the total cost + the path of subsequent <code>NodeId</code> from start to finish, if one was
found.</p>
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