cwtests/cw03/collatz2.while
author Christian Urban <christian.urban@kcl.ac.uk>
Fri, 24 Oct 2025 11:26:43 +0100
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Christian Urban <christian.urban@kcl.ac.uk>
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// Collatz series
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Christian Urban <christian.urban@kcl.ac.uk>
parents:
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//
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Christian Urban <christian.urban@kcl.ac.uk>
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// needs writing of strings and numbers; comments
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Christian Urban <christian.urban@kcl.ac.uk>
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Christian Urban <christian.urban@kcl.ac.uk>
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bnd := 1;
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Christian Urban <christian.urban@kcl.ac.uk>
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while bnd < 101 do {
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Christian Urban <christian.urban@kcl.ac.uk>
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  write bnd;
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Christian Urban <christian.urban@kcl.ac.uk>
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  write ": ";
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Christian Urban <christian.urban@kcl.ac.uk>
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  n := bnd;
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Christian Urban <christian.urban@kcl.ac.uk>
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  cnt := 0;
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Christian Urban <christian.urban@kcl.ac.uk>
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Christian Urban <christian.urban@kcl.ac.uk>
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  while n > 1 do {
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Christian Urban <christian.urban@kcl.ac.uk>
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    write n;
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Christian Urban <christian.urban@kcl.ac.uk>
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    write ",";
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Christian Urban <christian.urban@kcl.ac.uk>
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Christian Urban <christian.urban@kcl.ac.uk>
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    if n % 2 == 0 
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Christian Urban <christian.urban@kcl.ac.uk>
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    then n := n / 2 
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Christian Urban <christian.urban@kcl.ac.uk>
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    else n := 3 * n+1;
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Christian Urban <christian.urban@kcl.ac.uk>
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Christian Urban <christian.urban@kcl.ac.uk>
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    cnt := cnt + 1
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Christian Urban <christian.urban@kcl.ac.uk>
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  };
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Christian Urban <christian.urban@kcl.ac.uk>
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Christian Urban <christian.urban@kcl.ac.uk>
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  write " => ";
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Christian Urban <christian.urban@kcl.ac.uk>
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  write cnt;
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Christian Urban <christian.urban@kcl.ac.uk>
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  write "\n";
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Christian Urban <christian.urban@kcl.ac.uk>
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  bnd := bnd + 1
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Christian Urban <christian.urban@kcl.ac.uk>
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}