Pythagorean triples: Difference between revisions

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* [[List comprehensions]]

=={{header|Ada}}==

Translation of efficient method from C, see [[wp:Pythagorean_triple#Parent.2Fchild_relationships|the same WP article]]. Compiled on gnat/gcc.

<lang Ada>with Ada.Text_IO;

procedure Pythagorean_Triples is

type Large_Natural is range 0 .. 2**63-1;

-- this is the maximum for gnat

procedure New_Triangle(A, B, C: Large_Natural;

Max_Perimeter: Large_Natural;

Total_Cnt, Primitive_Cnt: in out Large_Natural) is

Perimeter: constant Large_Natural := A + B + C;

begin

if Perimeter <= Max_Perimeter then

Primitive_Cnt := Primitive_Cnt + 1;

Total_Cnt := Total_Cnt + Max_Perimeter / Perimeter;

New_Triangle(A-2*B+2*C, 2*A-B+2*C, 2*A-2*B+3*C,

Max_Perimeter, Total_Cnt, Primitive_Cnt);

New_Triangle(A+2*B+2*C, 2*A+B+2*C, 2*A+2*B+3*C,

Max_Perimeter, Total_Cnt, Primitive_Cnt);

New_Triangle(2*B+2*C-A, B+2*C-2*A, 2*B+3*C-2*A,

Max_Perimeter, Total_Cnt, Primitive_Cnt);

end if;

end New_Triangle;

T_Cnt, P_Cnt: Large_Natural;

begin

for I in 1 .. 8 loop

T_Cnt := 0;

P_Cnt := 0;

New_Triangle(3,4,5, 10**I, Total_Cnt => T_Cnt, Primitive_Cnt => P_Cnt);

Ada.Text_IO.Put_Line("Up to 10 **" & Integer'Image(I) & " :" &

Large_Natural'Image(T_Cnt) & " Triples," &

Large_Natural'Image(P_Cnt) & " Primitives");

end loop;

end Pythagorean_Triples;</lang>

Output:

<pre>Up to 10 ** 1 : 0 Triples, 0 Primitives

Up to 10 ** 2 : 17 Triples, 7 Primitives

Up to 10 ** 3 : 325 Triples, 70 Primitives

Up to 10 ** 4 : 4858 Triples, 703 Primitives

Up to 10 ** 5 : 64741 Triples, 7026 Primitives

Up to 10 ** 6 : 808950 Triples, 70229 Primitives

Up to 10 ** 7 : 9706567 Triples, 702309 Primitives

Up to 10 ** 8 : 113236940 Triples, 7023027 Primitives</pre>

=={{header|C}}==

Sample implemention; naive method, patentedly won't scale to larger numbers, despite the attempt to optimize it. Calculating up to 10000 is already a test of patience.

<lang C>#include <stdio.h>