Pythagorean triples: Difference between revisions

</pre>

=={{header|ERRE}}==

<lang ERRE>

PROGRAM PIT

BEGIN

PRINT(CHR$(12);) !CLS

PRINT(TIME$)

FOR POWER=1 TO 7 DO

PLIMIT=10#^POWER

UPPERBOUND=INT(1+PLIMIT^0.5)

PRIMITIVES=0

TRIPLES=0

EXTRAS=0 ! will count the in-range multiples of any primitive

FOR M=2 TO UPPERBOUND DO

FOR N=1+(M MOD 2=1) TO M-1 STEP 2 DO

TERM1=2*M*N

TERM2=M*M-N*N

TERM3=M*M+N*N

PERIMETER=TERM1+TERM2+TERM3

IF PERIMETER<=PLIMIT THEN TRIPLES=TRIPLES+1

A=TERM1

B=TERM2

REPEAT

R=A-B*INT(A/B)

A=B

B=R

UNTIL R<=0

! we've found a primitive triple if a = 1, since hcf =1.

! and it is inside perimeter range. Save it in an array

IF (A=1) AND (PERIMETER<=PLIMIT) THEN

PRIMITIVES=PRIMITIVES+1

!-----------------------------------------------

!swap so in increasing order of side length

!-----------------------------------------------

IF TERM1>TERM2 THEN SWAP(TERM1,TERM2)

!-----------------------------------------------

!we have the primitive & removed any multiples.

!Now calculate ALL the multiples in range.

!-----------------------------------------------

NEX=INT(PLIMIT/PERIMETER)

EXTRAS=EXTRAS+NEX

END IF

!scan

END FOR

END FOR

PRINT("Primit. with perimeter <=";10#^power;"is";primitives;"&";extras;"non-prim.triples.")

PRINT(TIME$)

END FOR

PRINT PRINT("** End **")

END PROGRAM</lang>

{{out}}

<pre>16:08:39

Primit. with perimeter <= 10 is 0 & 0 non-prim.triples.

16:08:39

Primit. with perimeter <= 100 is 7 & 17 non-prim.triples.

16:08:39

Primit. with perimeter <= 1000 is 70 & 325 non-prim.triples.

16:08:39

Primit. with perimeter <= 10000 is 703 & 4858 non-prim.triples.

16:08:39

Primit. with perimeter <= 100000 is 7026 & 64741 non-prim.triples.

16:08:41

Primit. with perimeter <= 1000000 is 70229 & 808950 non-prim.triples.

16:09:07

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