TPK algorithm: Difference between revisions

Revision as of 00:42, 20 June 2007

Revision as of 04:26, 20 June 2007

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==The algorithm==

In [[ALGOL 60]]:

<sourcecode lang="pascalalgol">

'''begin integer''' i; '''real''' y; '''real array''' a[0:10];

'''real procedure''' f(t); '''real''' t; '''value''' t;

f := sqrt(abs(t))+5×t↑35*t^3;

'''for''' i := 0 '''step''' 1 '''until''' 10 '''do''' read(a[i]);

'''for''' i := 10 '''step''' -1 '''until''' 0 '''do'''

'''begin''' y := f(a[i]);

'''if''' y > 400 '''then''' write(i, "TOO LARGE")

'''else''' write(i,y);

'''end'''

'''end'''

</sourcecode>

The algorithm reads eleven numbers from an input device, stores them in an array, and then processes them in reverse order, applying a user-defined function to each value and reporting either the value of the function or a message to the effect that the value has exceeded some threshold.

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The following [[Perl]] implementation is 79 [[byte]]s.

<sourcecode lang="perl">

map print(($_>400?"TOO LARGE":$_).$/),reverse map 5*($x=<>)**3+sqrt abs$x,1..11

</sourcecode>

==Python version==

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else:

print i, y

</source>

==Ruby version==

The following Ruby version makes heavy use of blocks / closures, as is common practice in the language:

<source lang="ruby">

f = proc { |t| (t.abs + 5 * t ** 3) ** 0.5 }

(1..11).map { f[gets.to_i] }.each_with_index { |t,u| puts u, t > 400 ? "TOO LARGE" : t }

</source>

Or, in a slightly longer, but more standard implementation:

<source lang="ruby">

a = []

f = lambda { |t| (t.abs + 5 * t ** 3) ** 0.5 }

11.times { a << gets.to_i }.times do |i|

j = f[a.shift]

puts i, j > 400 ? "TOO LARGE" : j

end

</source>