Smallest square that begins with n: Difference between revisions
→{{trans|Julia}}: speed up julia version. Stop searching as early as possible.Minimize divisions. 335 ms -> 71 ms :-)
(→{{trans|Julia}}: speed up julia version. Stop searching as early as possible.Minimize divisions. 335 ms -> 71 ms :-)) |
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</pre>
===={{trans|Julia}}====
Storing only the root ( n_running ) of the square so Uint32 suffices for the result.<br>
Improved version<br>
Stop searching as early as possible->minimize count of divisions.335 ms -> 71 ms :-)
<syntaxhighlight lang="pascal">
program smsq;
{$IFDEF FPC}{$MODE DELPHI}{$OPTIMIZATION ON,ALL}{$ENDIF}
uses
Line 2,221 ⟶ 2,223:
function smsq(n:Uint32):tRes;
var
k,Pow10 : Uint64;
n_running,found : Uint32;
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found := 0;
n_running := 1;
Pow10 := 1;
while found < n do
begin
k := sqr(n_running);
k := k div pow10;
while
result[k] := n_running;▼
found += 1;▼
end;▼
k := k div 10;
pow10 *=10;
end;
repeat
//no need to test any more
//if found ex. 4567 than 456,45 and 4 already marked before
if result[k] <> 0 then
k := k div 10;
until k = 0;
inc(n_running);
end
Line 2,275 ⟶ 2,285:
3136 324 3364 3481 35344 36 3721 3844 3969 400
41209 4225 4356 441 45369 4624 4761 484 49
check 1..10000000 in
=={{header|Perl}}==
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