Docs: Add TSP

docs-src/problems.md

@@ -20,6 +20,8 @@ To illustrate the performance of `LearningSolver`, and to set a baseline for new
 
 All experiments presented here were performed on a Linux server (Ubuntu Linux 18.04 LTS) with Intel Xeon Gold 6230s (2 processors, 40 cores, 80 threads) and 256 GB RAM (DDR4, 2933 MHz). All solvers were restricted to use 4 threads, with no time limits, and 10 instances were solved simultaneously at a time.
 
+
+
 ## Maximum Weight Stable Set Problem
 
 ### Problem definition
@@ -45,6 +47,8 @@ MaxWeightStableSetGenerator(w=uniform(loc=100., scale=50.),
 
 ![alt](figures/benchmark_stab_a.png)
 
+
+
 ## Multidimensional 0-1 Knapsack Problem
 
 ### Problem definition
@@ -115,3 +119,31 @@ MultiKnapsackGenerator(n=randint(low=250, high=251),
 ```
 
 ![alt](figures/benchmark_knapsack_a.png)
+
+
+
+## Traveling Salesman Problem
+
+### Problem definition
+
+Given a list of cities and the distance between each pair of cities, the problem asks for the
+shortest route starting at the first city, visiting each other city exactly once, then returning
+to the first city. This problem is a generalization of the Hamiltonian path problem, one of Karp's
+21 NP-complete problems.
+
+### Random problem generator
+
+The class `TravelingSalesmanGenerator` can be used to generate random instances of this
+problem. Initially, the generator creates $n$ cities $(x_1,y_1),\ldots,(x_n,y_n) \in \mathbb{R}^2$,
+where $n, x_i$ and $y_i$ are sampled independently from the provided probability distributions `n`,
+`x` and `y`. For each pair of cities $(i,j)$, the distance $d_{i,j}$ between them is set to:
+$$
+    d_{i,j} = \gamma_{i,j} \sqrt{(x_i-x_j)^2 + (y_i - y_j)^2}
+$$
+where $\gamma_{i,j}$ is sampled from the distribution `gamma`.
+
+If `fix_cities=True` is provided, the list of cities is kept the same for all generated instances.
+The $gamma$ values, and therefore also the distances, are still different.
+
+By default, all distances $d_{i,j}$ are rounded to the nearest integer.  If `round=False`
+is provided, this rounding will be disabled.

docs/404.html

@@ -14,16 +14,14 @@
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-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/all.css">
+    <link rel="stylesheet" href="//use.fontawesome.com/releases/v5.5.0/css/all.css" integrity="sha384-B4dIYHKNBt8Bc12p+WXckhzcICo0wtJAoU8YZTY5qE0Id1GSseTk6S+L3BlXeVIU" crossorigin="anonymous">
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+    <link href='//fonts.googleapis.com/css?family=PT+Sans:400,400italic,700,700italic&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
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@@ -151,7 +149,8 @@
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     <script src="//ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
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+    <script src="/js/highlight.pack.js"></script>
+    <script>hljs.initHighlightingOnLoad();</script>
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     <script src="/js/base.js"></script>
@@ -163,11 +162,8 @@
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         <div class="modal-content">
             <div class="modal-header">
-                <button type="button" class="close" data-dismiss="modal">
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-                    <span class="sr-only">Close</span>
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                 <h4 class="modal-title" id="searchModalLabel">Search</h4>
+                <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button>
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docs/about/index.html

@@ -14,16 +14,14 @@
     <title>About - MIPLearn</title>
     
 
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/all.css">
+    <link rel="stylesheet" href="//use.fontawesome.com/releases/v5.5.0/css/all.css" integrity="sha384-B4dIYHKNBt8Bc12p+WXckhzcICo0wtJAoU8YZTY5qE0Id1GSseTk6S+L3BlXeVIU" crossorigin="anonymous">
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/v4-shims.css">
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-    <link href='//rsms.me/inter/inter.css' rel='stylesheet' type='text/css'>
+    <link href='//fonts.googleapis.com/css?family=PT+Sans:400,400italic,700,700italic&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
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+    <link href="../css/highlight.min.css" rel="stylesheet">
-    
     <link href="../css/custom.css" rel="stylesheet">
 
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@@ -209,7 +207,8 @@ POSSIBILITY OF SUCH DAMAGE.
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+    <script src="../js/highlight.pack.js"></script>
+    <script>hljs.initHighlightingOnLoad();</script>
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@@ -221,11 +220,8 @@ POSSIBILITY OF SUCH DAMAGE.
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docs/benchmark/index.html

@@ -14,16 +14,14 @@
     <title>Benchmark - MIPLearn</title>
     
 
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/all.css">
+    <link rel="stylesheet" href="//use.fontawesome.com/releases/v5.5.0/css/all.css" integrity="sha384-B4dIYHKNBt8Bc12p+WXckhzcICo0wtJAoU8YZTY5qE0Id1GSseTk6S+L3BlXeVIU" crossorigin="anonymous">
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-    <link href='//rsms.me/inter/inter.css' rel='stylesheet' type='text/css'>
+    <link href='//fonts.googleapis.com/css?family=PT+Sans:400,400italic,700,700italic&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
     <link href='//fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,700italic,400,300,600,700&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
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     <link href="../css/base.min.css" rel="stylesheet">
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+    <link href="../css/highlight.min.css" rel="stylesheet">
-    
     <link href="../css/custom.css" rel="stylesheet">
 
     <!-- HTML5 shim and Respond.js IE8 support of HTML5 elements and media queries -->
@@ -218,7 +216,8 @@ benchmark.parallel_solve(test_instances)
     </footer>
     <script src="//ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
     <script src="../js/bootstrap-3.0.3.min.js"></script>
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+    <script src="../js/highlight.pack.js"></script>
+    <script>hljs.initHighlightingOnLoad();</script>
     <script>var base_url = ".."</script>
     
     <script src="../js/base.js"></script>
@@ -230,11 +229,8 @@ benchmark.parallel_solve(test_instances)
     <div class="modal-dialog modal-lg">
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docs/css/cinder.css

@@ -10,28 +10,23 @@ body {
     color: #343838;
 }
 h1, h2, h3, h4, h5, h6 {
-    font-family:'Inter', 'Helvetica Neue', Helvetica, Arial, sans-serif;
+    font-family:'PT Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif;
     color: #222;
 }
 h1 small, h2 small, h3 small, h4 small, h5 small, h6 small, .h1 small, .h2 small, .h3 small, .h4 small, .h5 small, .h6 small, h1 .small, h2 .small, h3 .small, h4 .small, h5 .small, h6 .small, .h1 .small, .h2 .small, .h3 .small, .h4 .small, .h5 .small, .h6 .small {
     color: #B1B7B9;
 }
-
-h2 {
-    margin-top: 35px;
-}
-
 h1, h2 {
     font-weight: 700;
 }
 h4 {
-    font-family: 'Inter', 'Helvetica Neue', Helvetica, Arial, sans-serif;
+    font-family: 'Open Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif;
     font-weight: 300;
     margin-top: 20px;
     font-style: italic;
 }
 h5 {
-    font-family: 'Inter', 'Helvetica Neue', Helvetica, Arial, sans-serif;
+    font-family: 'Open Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif;
     font-weight: 300;
     font-variant: small-caps;
 }
@@ -46,7 +41,7 @@ pre {
     margin-bottom: 25px;
 }
 .lead {
-    font-family:"Inter", "Helvetica Neue", Helvetica, Arial, sans-serif;
+    font-family:"Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
     font-weight: 400;
     line-height: 1.4;
     letter-spacing: 0.0312em;
@@ -59,8 +54,7 @@ pre {
 .bs-sidenav {
     background-image: url("../img/grid11.png");
     background-repeat: repeat;
-    font-family: Inter,"Helvetica Neue",Helvetica,Arial,sans-serif;
+    font-size: 12px;
-    font-size: 13px;
 }
 .well {
     background-color: #FCFDFF;
@@ -77,7 +71,7 @@ pre {
     box-shadow: none;
 }
 #mkdocs-search-query {
-    font-family:"Inter", "Helvetica Neue", Helvetica, Arial, sans-serif;
+    font-family:"Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
     font-size: 20px;
     font-weight: 700;
     color: #343838;

docs/css/cinder.min.css

@@ -1 +1 @@
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+body{font-family:"Open Sans","Helvetica Neue",Helvetica,Arial,sans-serif;font-size:16px;line-height:1.7;background-color:#FFF;color:#343838}h1,h2,h3,h4,h5,h6{font-family:'PT Sans','Helvetica Neue',Helvetica,Arial,sans-serif;color:#222}h1 small,h2 small,h3 small,h4 small,h5 small,h6 small,.h1 small,.h2 small,.h3 small,.h4 small,.h5 small,.h6 small,h1 .small,h2 .small,h3 .small,h4 .small,h5 .small,h6 .small,.h1 .small,.h2 .small,.h3 .small,.h4 .small,.h5 .small,.h6 .small{color:#b1b7b9}h1,h2{font-weight:700}h4{font-family:'Open Sans','Helvetica Neue',Helvetica,Arial,sans-serif;font-weight:300;margin-top:20px;font-style:italic}h5{font-family:'Open Sans','Helvetica Neue',Helvetica,Arial,sans-serif;font-weight:300;font-variant:small-caps}pre,code{background-color:#fcfdff}pre>code{font-size:13px}pre{margin-top:25px;margin-bottom:25px}.lead{font-family:"Open Sans","Helvetica Neue",Helvetica,Arial,sans-serif;font-weight:400;line-height:1.4;letter-spacing:.0312em;color:#b1b7b9}.navbar-default{background-color:#343838;border-bottom:8px #ebf2f2 solid}.bs-sidenav{background-image:url("../img/grid11.png");background-repeat:repeat;font-size:12px}.well{background-color:#fcfdff}.btn-default{background-color:#fcfdff}.table-striped>tbody>tr:nth-child(2n+1)>td,.table-striped>tbody>tr:nth-child(2n+1)>th{background-color:#fcfdff}#mkdocs-search-query:focus{outline:0;-webkit-box-shadow:none;box-shadow:none}#mkdocs-search-query{font-family:"Open Sans","Helvetica Neue",Helvetica,Arial,sans-serif;font-size:20px;font-weight:700;color:#343838;height:45px}footer>hr{width:35%}

docs/customization/index.html

@@ -14,16 +14,14 @@
     <title>Customization - MIPLearn</title>
     
 
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/all.css">
+    <link rel="stylesheet" href="//use.fontawesome.com/releases/v5.5.0/css/all.css" integrity="sha384-B4dIYHKNBt8Bc12p+WXckhzcICo0wtJAoU8YZTY5qE0Id1GSseTk6S+L3BlXeVIU" crossorigin="anonymous">
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/v4-shims.css">
     <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/hack-font@3.3.0/build/web/hack.min.css">
-    <link href='//rsms.me/inter/inter.css' rel='stylesheet' type='text/css'>
+    <link href='//fonts.googleapis.com/css?family=PT+Sans:400,400italic,700,700italic&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
     <link href='//fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,700italic,400,300,600,700&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
     <link href="../css/bootstrap-custom.min.css" rel="stylesheet">
     <link href="../css/base.min.css" rel="stylesheet">
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+    <link href="../css/highlight.min.css" rel="stylesheet">
-    
     <link href="../css/custom.css" rel="stylesheet">
 
     <!-- HTML5 shim and Respond.js IE8 support of HTML5 elements and media queries -->
@@ -171,7 +169,8 @@ solver = LearningSolver(solver=&quot;cplex&quot;,
     </footer>
     <script src="//ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
     <script src="../js/bootstrap-3.0.3.min.js"></script>
-    
+    <script src="../js/highlight.pack.js"></script>
+    <script>hljs.initHighlightingOnLoad();</script>
     <script>var base_url = ".."</script>
     
     <script src="../js/base.js"></script>
@@ -183,11 +182,8 @@ solver = LearningSolver(solver=&quot;cplex&quot;,
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+                <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button>
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@@ -14,16 +14,14 @@
     <title>Home - MIPLearn</title>
     
 
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/all.css">
+    <link rel="stylesheet" href="//use.fontawesome.com/releases/v5.5.0/css/all.css" integrity="sha384-B4dIYHKNBt8Bc12p+WXckhzcICo0wtJAoU8YZTY5qE0Id1GSseTk6S+L3BlXeVIU" crossorigin="anonymous">
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/v4-shims.css">
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-    <link href='//rsms.me/inter/inter.css' rel='stylesheet' type='text/css'>
+    <link href='//fonts.googleapis.com/css?family=PT+Sans:400,400italic,700,700italic&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
     <link href='//fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,700italic,400,300,600,700&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
     <link href="css/bootstrap-custom.min.css" rel="stylesheet">
     <link href="css/base.min.css" rel="stylesheet">
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+    <link href="css/highlight.min.css" rel="stylesheet">
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@@ -197,7 +195,8 @@
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     <script src="//ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
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+    <script src="js/highlight.pack.js"></script>
+    <script>hljs.initHighlightingOnLoad();</script>
     <script>var base_url = "."</script>
     
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@@ -209,11 +208,8 @@
     <div class="modal-dialog modal-lg">
         <div class="modal-content">
             <div class="modal-header">
-                <button type="button" class="close" data-dismiss="modal">
-                    <span aria-hidden="true">&times;</span>
-                    <span class="sr-only">Close</span>
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                 <h4 class="modal-title" id="searchModalLabel">Search</h4>
+                <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button>
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@@ -277,5 +273,5 @@
 
 <!--
 MkDocs version : 1.0.4
-Build Date UTC : 2020-02-24 16:57:12
+Build Date UTC : 2020-02-25 04:02:08
 -->

docs/problems/index.html

@@ -14,16 +14,14 @@
     <title>Problems - MIPLearn</title>
     
 
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/all.css">
+    <link rel="stylesheet" href="//use.fontawesome.com/releases/v5.5.0/css/all.css" integrity="sha384-B4dIYHKNBt8Bc12p+WXckhzcICo0wtJAoU8YZTY5qE0Id1GSseTk6S+L3BlXeVIU" crossorigin="anonymous">
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-    <link href='//rsms.me/inter/inter.css' rel='stylesheet' type='text/css'>
+    <link href='//fonts.googleapis.com/css?family=PT+Sans:400,400italic,700,700italic&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
     <link href='//fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,700italic,400,300,600,700&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
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     <link href="../css/base.min.css" rel="stylesheet">
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@@ -154,6 +152,10 @@
                 <li class="third-level"><a href="#problem-definition_1">Problem definition</a></li>
                 <li class="third-level"><a href="#random-instance-generator_1">Random instance generator</a></li>
                 <li class="third-level"><a href="#challenge-a_1">Challenge A</a></li>
+            <li class="second-level"><a href="#traveling-salesman-problem">Traveling Salesman Problem</a></li>
+                
+                <li class="third-level"><a href="#problem-definition_2">Problem definition</a></li>
+                <li class="third-level"><a href="#random-problem-generator">Random problem generator</a></li>
     </ul>
 </div></div>
         <div class="col-md-9" role="main">
@@ -251,7 +253,26 @@ from the provided probability distributions <code>K</code> and <code>u</code>.</
                       )
 </code></pre>
 
-<p><img alt="alt" src="../figures/benchmark_knapsack_a.png" /></p></div>
+<p><img alt="alt" src="../figures/benchmark_knapsack_a.png" /></p>
+<h2 id="traveling-salesman-problem">Traveling Salesman Problem</h2>
+<h3 id="problem-definition_2">Problem definition</h3>
+<p>Given a list of cities and the distance between each pair of cities, the problem asks for the
+shortest route starting at the first city, visiting each other city exactly once, then returning
+to the first city. This problem is a generalization of the Hamiltonian path problem, one of Karp's
+21 NP-complete problems.</p>
+<h3 id="random-problem-generator">Random problem generator</h3>
+<p>The class <code>TravelingSalesmanGenerator</code> can be used to generate random instances of this
+problem. Initially, the generator creates $n$ cities $(x_1,y_1),\ldots,(x_n,y_n) \in \mathbb{R}^2$,
+where $n, x_i$ and $y_i$ are sampled independently from the provided probability distributions <code>n</code>,
+<code>x</code> and <code>y</code>. For each pair of cities $(i,j)$, the distance $d_{i,j}$ between them is set to:
+<script type="math/tex; mode=display">
+    d_{i,j} = \gamma_{i,j} \sqrt{(x_i-x_j)^2 + (y_i - y_j)^2}
+</script>
+where $\gamma_{i,j}$ is sampled from the distribution <code>gamma</code>.</p>
+<p>If <code>fix_cities=True</code> is provided, the list of cities is kept the same for all generated instances.
+The $gamma$ values, and therefore also the distances, are still different.</p>
+<p>By default, all distances $d_{i,j}$ are rounded to the nearest integer.  If <code>round=False</code>
+is provided, this rounding will be disabled.</p></div>
         
         
     </div>
@@ -269,7 +290,8 @@ from the provided probability distributions <code>K</code> and <code>u</code>.</
     </footer>
     <script src="//ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
     <script src="../js/bootstrap-3.0.3.min.js"></script>
-    
+    <script src="../js/highlight.pack.js"></script>
+    <script>hljs.initHighlightingOnLoad();</script>
     <script>var base_url = ".."</script>
     
     <script src="../js/base.js"></script>
@@ -281,11 +303,8 @@ from the provided probability distributions <code>K</code> and <code>u</code>.</
     <div class="modal-dialog modal-lg">
         <div class="modal-content">
             <div class="modal-header">
-                <button type="button" class="close" data-dismiss="modal">
-                    <span aria-hidden="true">&times;</span>
-                    <span class="sr-only">Close</span>
-                </button>
                 <h4 class="modal-title" id="searchModalLabel">Search</h4>
+                <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button>
             </div>
             <div class="modal-body">
                 <p>

docs/usage/index.html

@@ -14,16 +14,14 @@
     <title>Usage - MIPLearn</title>
     
 
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/all.css">
+    <link rel="stylesheet" href="//use.fontawesome.com/releases/v5.5.0/css/all.css" integrity="sha384-B4dIYHKNBt8Bc12p+WXckhzcICo0wtJAoU8YZTY5qE0Id1GSseTk6S+L3BlXeVIU" crossorigin="anonymous">
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/v4-shims.css">
     <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/hack-font@3.3.0/build/web/hack.min.css">
-    <link href='//rsms.me/inter/inter.css' rel='stylesheet' type='text/css'>
+    <link href='//fonts.googleapis.com/css?family=PT+Sans:400,400italic,700,700italic&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
     <link href='//fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,700italic,400,300,600,700&subset=latin-ext,latin' rel='stylesheet' type='text/css'>
     <link href="../css/bootstrap-custom.min.css" rel="stylesheet">
     <link href="../css/base.min.css" rel="stylesheet">
     <link href="../css/cinder.min.css" rel="stylesheet">
-
+    <link href="../css/highlight.min.css" rel="stylesheet">
-    
     <link href="../css/custom.css" rel="stylesheet">
 
     <!-- HTML5 shim and Respond.js IE8 support of HTML5 elements and media queries -->
@@ -254,7 +252,8 @@ solver.solve(test_instance)
     </footer>
     <script src="//ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
     <script src="../js/bootstrap-3.0.3.min.js"></script>
-    
+    <script src="../js/highlight.pack.js"></script>
+    <script>hljs.initHighlightingOnLoad();</script>
     <script>var base_url = ".."</script>
     
     <script src="../js/base.js"></script>
@@ -266,11 +265,8 @@ solver.solve(test_instance)
     <div class="modal-dialog modal-lg">
         <div class="modal-content">
             <div class="modal-header">
-                <button type="button" class="close" data-dismiss="modal">
-                    <span aria-hidden="true">&times;</span>
-                    <span class="sr-only">Close</span>
-                </button>
                 <h4 class="modal-title" id="searchModalLabel">Search</h4>
+                <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button>
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             <div class="modal-body">
                 <p>