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Pythagorean quadruples: Difference between revisions
→{{header|Pascal}}: added Version 2 like REXX optimized
m (→{{header|Pascal}}: Give i386 a chance und improved runtime for both Cpu64/Cpu32 :-)) |
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</pre>
=={{header|Pascal}}==
{{works with|Free Pascal}}
===version 1===
Brute froce, but not as brute as [http://rosettacode.org/mw/index.php?title=Pythagorean_quadruples#Ring Ring].Did it ever run?<BR>
Stopping search if limit is reached<BR>
<lang pascal>program pythQuad;
Line 1,200 ⟶ 1,202:
929605937 checks were done
real 0m2.323s -> 9 cpu-cycles per check on Ryzen 5 1600 3,7 Ghz ( Turbo )
</pre>
===version 2===
Using a variant of [http://rosettacode.org/wiki/Pythagorean_quadruples#optimized REXX optimized] optimized<BR>Quite fast.
<lang pascal>program pythQuad_2;
//find phythagorean Quadrupel up to a,b,c,d <= 2200
//a^2 + b^2 +c^2 = d^2
//a^2 + b^2 = d^2-c^2
const
MaxFactor =2200;
limit = MaxFactor*MaxFactor;
type
tIdx = NativeUint;
tSum = NativeUint;
var
// global variables are initiated with 0 at startUp
sumA2B2 :array[0..limit] of byte;
check : array[0..MaxFactor] of byte;
procedure BuildSumA2B2;
var
a,b : tIdx;
s : tSum;
begin
For a := 1 to MaxFactor do
For b := a to MaxFactor do
Begin
s := a*a+b*b;
if s < limit then
sumA2B2[s] := 1
else
break;
end;
end;
procedure CheckDifD2C2;
var
d,c : tIdx;
s : tSum;
begin
For d := 1 to MaxFactor do
//c < d => (d*d-c*c) > 0
For c := d-1 downto 1 do
Begin
s := d*d-c*c;
if sumA2B2[s] <> 0 then
Check[d] := 1;
end;
end;
var
i : NativeUint;
begin
BuildSumA2B2;
CheckDifD2C2;
//FindHoles;
For i := 1 to MaxFactor do
If Check[i] = 0 then
write(i,' ');
writeln;
end.</lang>
{{Out}}
<pre>
1 2 4 5 8 10 16 20 32 40 64 80 128 160 256 320 512 640 1024 1280 2048
real 0m0.018s //4.8 Mb -> Level 3 cache 16 Mb ( Ryzen 5 1600 )
//MaxFactor =22000;484 Mb -> no level X Cache
1 2 4 5 8 10 16 20 32 40 64 80 128 160 256 320 512 640 1024 1280 2048 2560 4096 5120 8192 10240 16384 20480
real 0m4.184s
</pre>
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