Rosetta Code

Word ladder: Difference between revisions

Page Discussion

Word ladder (view source)

Revision as of 15:58, 5 June 2021

8,322 bytes added ,  2 years ago
→‎{{header|Phix}}
(Created page with "{{Draft task}} Yet another shortest path problem. Given two words of equal length the task is to transpose the first into the second. Only one letter may be changed at a time...")
 
Line 35:
john -> cohn -> conn -> cone -> cane -> jane
child into adult can't be done
</pre>
 
=={{header|Phix}}==
<!--<lang Phix>(notonline)-->
<span style="color: #004080;">sequence</span> <span style="color: #000000;">words</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">get_text</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"demo/unixdict.txt"</span><span style="color: #0000FF;">,</span><span style="color: #004600;">GT_LF_STRIPPED</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">right_length</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</span> <span style="color: #000000;">word</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">l</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">word</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">l</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">one_away</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</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: #008080;">return</span> <span style="color: #7060A8;">sum</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">sq_ne</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;">1</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">word_ladder</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</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: #004080;">sequence</span> <span style="color: #000000;">poss</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">filter</span><span style="color: #0000FF;">(</span><span style="color: #000000;">words</span><span style="color: #0000FF;">,</span><span style="color: #000000;">right_length</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span><span style="color: #0000FF;">)),</span>
<span style="color: #000000;">todo</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;">curr</span> <span style="color: #000080;font-style:italic;">-- aka todo[1], word chain starting from a</span>
<span style="color: #008080;">while</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">todo</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
<span style="color: #0000FF;">{</span><span style="color: #000000;">curr</span><span style="color: #0000FF;">,</span><span style="color: #000000;">todo</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">todo</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">],</span><span style="color: #000000;">todo</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">..$]}</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">next</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">filter</span><span style="color: #0000FF;">(</span><span style="color: #000000;">poss</span><span style="color: #0000FF;">,</span><span style="color: #000000;">one_away</span><span style="color: #0000FF;">,</span><span style="color: #000000;">curr</span><span style="color: #0000FF;">[$])</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">b</span><span style="color: #0000FF;">,</span><span style="color: #000000;">next</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</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;">"%s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">curr</span><span style="color: #0000FF;">,</span><span style="color: #000000;">b</span><span style="color: #0000FF;">),</span><span style="color: #008000;">"-&gt;"</span><span style="color: #0000FF;">)})</span>
<span style="color: #008080;">return</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">poss</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">filter</span><span style="color: #0000FF;">(</span><span style="color: #000000;">poss</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"out"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">next</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">todo</span> <span style="color: #0000FF;">&=</span> <span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">append</span><span style="color: #0000FF;">,{{</span><span style="color: #000000;">curr</span><span style="color: #0000FF;">},</span><span style="color: #000000;">next</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</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;">"%s into %s cannot be done\n"</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: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #000000;">word_ladder</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"boy"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"man"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">word_ladder</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"girl"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"lady"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">word_ladder</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"john"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"jane"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">word_ladder</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"child"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"adult"</span><span style="color: #0000FF;">)</span>
<!--</lang>-->
{{out}}
<pre>
boy->bay->ban->man
girl->gill->gall->gale->gaze->laze->lazy->lady
john->cohn->conn->cone->cane->jane
child into adult cannot be done
</pre>
Petelomax
7,803

edits

Retrieved from "https://rosettacode.org/wiki/Special:MobileDiff/312851"