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<h1 style="color: #145A32;">C++ Reference: Routing</h1>
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<p><a href="constraint__solver_8h_source.html">Go to the source code of this file.</a></p>
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Functions</h2></td></tr>
<tr class="memitem:a7c38c1c8e88571b510def97ee8bd5804"><td class="memItemLeft" align="right" valign="top">&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="constraint__solver_8h.html#a7c38c1c8e88571b510def97ee8bd5804">DECLARE_int64</a> (cp_random_seed)</td></tr>
<tr class="memdesc:a7c38c1c8e88571b510def97ee8bd5804"><td class="mdescLeft">&#160;</td><td class="mdescRight">Declaration of the core objects for the constraint solver. <a href="constraint__solver_8h.html#a7c38c1c8e88571b510def97ee8bd5804">More...</a><br /></td></tr>
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<h2 class="memtitle"><span class="permalink"><a href="#a7c38c1c8e88571b510def97ee8bd5804">&#9670;&nbsp;</a></span>DECLARE_int64()</h2>
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<td class="memname">DECLARE_int64 </td>
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<p>Declaration of the core objects for the constraint solver. </p>
<p>The literature around constraint programming is extremely dense but one can find some basic introductions in the following links:</p><ul>
<li><a href="http://en.wikipedia.org/wiki/Constraint_programming">http://en.wikipedia.org/wiki/Constraint_programming</a></li>
<li><a href="http://kti.mff.cuni.cz/~bartak/constraints/index.html">http://kti.mff.cuni.cz/~bartak/constraints/index.html</a></li>
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<p>Here is a very simple Constraint Programming problem:</p>
<p>Knowing that we see 56 legs and 20 heads, how many pheasants and rabbits are we looking at?</p>
<p>Here is some simple Constraint Programming code to find out:</p>
<p>void pheasant() { Solver s("pheasant"); IntVar* const p = s.MakeIntVar(0, 20, "pheasant")); IntVar* const r = s.MakeIntVar(0, 20, "rabbit")); IntExpr* const legs = s.MakeSum(s.MakeProd(p, 2), s.MakeProd(r, 4)); IntExpr* const heads = s.MakeSum(p, r); Constraint* const ct_legs = s.MakeEquality(legs, 56); Constraint* const ct_heads = s.MakeEquality(heads, 20); s.AddConstraint(ct_legs); s.AddConstraint(ct_heads); DecisionBuilder* const db = s.MakePhase(p, r, Solver::CHOOSE_FIRST_UNBOUND, Solver::ASSIGN_MIN_VALUE); s.NewSearch(db); CHECK(s.NextSolution()); LOG(INFO) &lt;&lt; "rabbits -&gt; " &lt;&lt; r-&gt;Value() &lt;&lt; ", pheasants -&gt; " &lt;&lt; p-&gt;Value(); LOG(INFO) &lt;&lt; s.DebugString(); s.EndSearch(); }</p>
<p>which outputs:</p>
<p>rabbits -&gt; 8, pheasants -&gt; 12 Solver(name = "pheasant", state = OUTSIDE_SEARCH, branches = 0, fails = 0, decisions = 0 propagation loops = 11, demons Run = 25, Run time = 0 ms) </p>
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