RosettaCodeData/Task/Dijkstras-algorithm/Phix/dijkstras-algorithm.phix

(phixonline)-->
 <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
 <span style="color: #000080;font-style:italic;">--requires("1.0.2") -- (builtin E renamed as EULER)
 --enum A,B,C,D,E,F</span>
 <span style="color: #008080;">constant</span> <span style="color: #000000;">A</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">B</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">C</span><span style="color: #0000FF;">=</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">D</span><span style="color: #0000FF;">=</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">E</span><span style="color: #0000FF;">=</span><span style="color: #000000;">5</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">F</span><span style="color: #0000FF;">=</span><span style="color: #000000;">6</span> <span style="color: #000080;font-style:italic;">-- (or use this)</span>
 <span style="color: #008080;">constant</span> <span style="color: #000000;">edges</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{</span><span style="color: #000000;">A</span><span style="color: #0000FF;">,</span><span style="color: #000000;">B</span><span style="color: #0000FF;">,</span><span style="color: #000000;">7</span><span style="color: #0000FF;">},</span>
                   <span style="color: #0000FF;">{</span><span style="color: #000000;">A</span><span style="color: #0000FF;">,</span><span style="color: #000000;">C</span><span style="color: #0000FF;">,</span><span style="color: #000000;">9</span><span style="color: #0000FF;">},</span>
                   <span style="color: #0000FF;">{</span><span style="color: #000000;">A</span><span style="color: #0000FF;">,</span><span style="color: #000000;">F</span><span style="color: #0000FF;">,</span><span style="color: #000000;">14</span><span style="color: #0000FF;">},</span>
                   <span style="color: #0000FF;">{</span><span style="color: #000000;">B</span><span style="color: #0000FF;">,</span><span style="color: #000000;">C</span><span style="color: #0000FF;">,</span><span style="color: #000000;">10</span><span style="color: #0000FF;">},</span>
                   <span style="color: #0000FF;">{</span><span style="color: #000000;">B</span><span style="color: #0000FF;">,</span><span style="color: #000000;">D</span><span style="color: #0000FF;">,</span><span style="color: #000000;">15</span><span style="color: #0000FF;">},</span>
                   <span style="color: #0000FF;">{</span><span style="color: #000000;">C</span><span style="color: #0000FF;">,</span><span style="color: #000000;">D</span><span style="color: #0000FF;">,</span><span style="color: #000000;">11</span><span style="color: #0000FF;">},</span>
                   <span style="color: #0000FF;">{</span><span style="color: #000000;">C</span><span style="color: #0000FF;">,</span><span style="color: #000000;">F</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">},</span>
                   <span style="color: #0000FF;">{</span><span style="color: #000000;">D</span><span style="color: #0000FF;">,</span><span style="color: #000000;">E</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">},</span>
                   <span style="color: #0000FF;">{</span><span style="color: #000000;">E</span><span style="color: #0000FF;">,</span><span style="color: #000000;">F</span><span style="color: #0000FF;">,</span><span style="color: #000000;">9</span><span style="color: #0000FF;">}}</span>

 <span style="color: #004080;">sequence</span> <span style="color: #000000;">visited</span><span style="color: #0000FF;">,</span>
          <span style="color: #000000;">cost</span><span style="color: #0000FF;">,</span>
          <span style="color: #000000;">from</span>

 <span style="color: #008080;">procedure</span> <span style="color: #000000;">reset</span><span style="color: #0000FF;">()</span>
     <span style="color: #000000;">visited</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">)</span>
     <span style="color: #000000;">cost</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">)</span>
     <span style="color: #000000;">from</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">)</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>

 <span style="color: #008080;">function</span> <span style="color: #000000;">backtrack</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">finish</span><span style="color: #0000FF;">,</span><span style="color: #000000;">start</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">sequence</span> <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">finish</span><span style="color: #0000FF;">}</span>
     <span style="color: #008080;">while</span> <span style="color: #000000;">finish</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">start</span> <span style="color: #008080;">do</span>
         <span style="color: #000000;">finish</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">from</span><span style="color: #0000FF;">[</span><span style="color: #000000;">finish</span><span style="color: #0000FF;">]</span>
         <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prepend</span><span style="color: #0000FF;">(</span><span style="color: #000000;">res</span><span style="color: #0000FF;">,</span><span style="color: #000000;">finish</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
     <span style="color: #008080;">return</span> <span style="color: #000000;">res</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>

 <span style="color: #008080;">function</span> <span style="color: #000000;">shortest_path</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">start</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">finish</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">integer</span> <span style="color: #000000;">estart</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">eend</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ecost</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ncost</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">mincost</span>
     <span style="color: #008080;">while</span> <span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
         <span style="color: #000000;">visited</span><span style="color: #0000FF;">[</span><span style="color: #000000;">start</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">edges</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
             <span style="color: #0000FF;">{</span><span style="color: #000000;">estart</span><span style="color: #0000FF;">,</span><span style="color: #000000;">eend</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ecost</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">edges</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
             <span style="color: #008080;">if</span> <span style="color: #000000;">estart</span><span style="color: #0000FF;">=</span><span style="color: #000000;">start</span> <span style="color: #008080;">then</span>
                 <span style="color: #000000;">ncost</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">cost</span><span style="color: #0000FF;">[</span><span style="color: #000000;">start</span><span style="color: #0000FF;">]+</span><span style="color: #000000;">ecost</span>
                 <span style="color: #008080;">if</span> <span style="color: #000000;">visited</span><span style="color: #0000FF;">[</span><span style="color: #000000;">eend</span><span style="color: #0000FF;">]=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
                     <span style="color: #008080;">if</span> <span style="color: #000000;">from</span><span style="color: #0000FF;">[</span><span style="color: #000000;">eend</span><span style="color: #0000FF;">]=</span><span style="color: #000000;">0</span>
                     <span style="color: #008080;">or</span> <span style="color: #000000;">cost</span><span style="color: #0000FF;">[</span><span style="color: #000000;">eend</span><span style="color: #0000FF;">]></span><span style="color: #000000;">ncost</span> <span style="color: #008080;">then</span>
                         <span style="color: #000000;">cost</span><span style="color: #0000FF;">[</span><span style="color: #000000;">eend</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">ncost</span>
                         <span style="color: #000000;">from</span><span style="color: #0000FF;">[</span><span style="color: #000000;">eend</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">start</span>
                     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
                 <span style="color: #008080;">elsif</span> <span style="color: #000000;">cost</span><span style="color: #0000FF;">[</span><span style="color: #000000;">eend</span><span style="color: #0000FF;">]></span><span style="color: #000000;">ncost</span> <span style="color: #008080;">then</span>
                     <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span>    <span style="color: #000080;font-style:italic;">-- sanity check</span>
                 <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
         <span style="color: #000000;">mincost</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">visited</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
             <span style="color: #008080;">if</span> <span style="color: #000000;">visited</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]=</span><span style="color: #000000;">0</span>
             <span style="color: #008080;">and</span> <span style="color: #000000;">from</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
                 <span style="color: #008080;">if</span> <span style="color: #000000;">mincost</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span>
                 <span style="color: #008080;">or</span> <span style="color: #000000;">cost</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]<</span><span style="color: #000000;">mincost</span> <span style="color: #008080;">then</span>
                     <span style="color: #000000;">start</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">i</span>
                     <span style="color: #000000;">mincost</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">cost</span><span style="color: #0000FF;">[</span><span style="color: #000000;">start</span><span style="color: #0000FF;">]</span>
                 <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">visited</span><span style="color: #0000FF;">[</span><span style="color: #000000;">start</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">1</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">start</span><span style="color: #0000FF;">=</span><span style="color: #000000;">finish</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #000000;">cost</span><span style="color: #0000FF;">[</span><span style="color: #000000;">finish</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>

 <span style="color: #008080;">function</span> <span style="color: #000000;">AFi</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">)</span>     <span style="color: #000080;font-style:italic;">-- output helper</span>
     <span style="color: #008080;">return</span> <span style="color: #008000;">'A'</span><span style="color: #0000FF;">+</span><span style="color: #000000;">i</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>

 <span style="color: #008080;">procedure</span> <span style="color: #000000;">test</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">testset</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">integer</span> <span style="color: #000000;">start</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">finish</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ecost</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">len</span>
     <span style="color: #004080;">string</span> <span style="color: #000000;">epath</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">path</span>
     <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">testset</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
         <span style="color: #0000FF;">{</span><span style="color: #000000;">start</span><span style="color: #0000FF;">,</span><span style="color: #000000;">finish</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ecost</span><span style="color: #0000FF;">,</span><span style="color: #000000;">epath</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">testset</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
         <span style="color: #000000;">reset</span><span style="color: #0000FF;">()</span>
         <span style="color: #000000;">len</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">shortest_path</span><span style="color: #0000FF;">(</span><span style="color: #000000;">start</span><span style="color: #0000FF;">,</span><span style="color: #000000;">finish</span><span style="color: #0000FF;">)</span>
         <span style="color: #000000;">path</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">len</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">?</span><span style="color: #008000;">"no path found"</span><span style="color: #0000FF;">:</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #000000;">backtrack</span><span style="color: #0000FF;">(</span><span style="color: #000000;">finish</span><span style="color: #0000FF;">,</span><span style="color: #000000;">start</span><span style="color: #0000FF;">),</span><span style="color: #000000;">AFi</span><span style="color: #0000FF;">),</span><span style="color: #008000;">""</span><span style="color: #0000FF;">))</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%c-&gt;%c: length %d:%s (expected %d:%s)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">AFi</span><span style="color: #0000FF;">(</span><span style="color: #000000;">start</span><span style="color: #0000FF;">),</span><span style="color: #000000;">AFi</span><span style="color: #0000FF;">(</span><span style="color: #000000;">finish</span><span style="color: #0000FF;">),</span><span style="color: #000000;">len</span><span style="color: #0000FF;">,</span><span style="color: #000000;">path</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ecost</span><span style="color: #0000FF;">,</span><span style="color: #000000;">epath</span><span style="color: #0000FF;">})</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>

 <span style="color: #000000;">test</span><span style="color: #0000FF;">({{</span><span style="color: #000000;">A</span><span style="color: #0000FF;">,</span><span style="color: #000000;">E</span><span style="color: #0000FF;">,</span><span style="color: #000000;">26</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"ACDE"</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">A</span><span style="color: #0000FF;">,</span><span style="color: #000000;">F</span><span style="color: #0000FF;">,</span><span style="color: #000000;">11</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"ACF"</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">F</span><span style="color: #0000FF;">,</span><span style="color: #000000;">A</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"none"</span><span style="color: #0000FF;">}})</span>
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