Pythagorean triples: Difference between revisions

=={{header|Tcl}}==

Using the efficient method based off the Wikipedia article:

{{works with|Tcl|8.6}}

<lang tcl>package require Tcl 8.6

proc gentrips {limit {a 3} {b 4} {c 5}} {

if {$a + $b + $c <= $limit} {

yield [list 1 1 $a $b $c]

for {set i 2} {$i*$a+$i*$b+$i*$c <= $limit} {incr i} {

yield [list 1 0 [expr {$a*$i}] [expr {$b*$i}] [expr {$c*$i}]]

}

gentrips $limit [expr {$a + 2*($c-$b)}] [expr {2*($a+$c) - $b}] [expr {2*($a-$b) + 3*$c}]

gentrips $limit [expr {$a + 2*($b+$c)}] [expr {2*($a+$c) + $b}] [expr {2*($a+$b) + 3*$c}]

gentrips $limit [expr {2*($b+$c) - $a}] [expr {2*($c-$a) + $b}] [expr {2*($b-$a) + 3*$c}]

}

return 0

}

proc countPythagoreanTriples n {

coroutine p eval "yield;gentrips $n"

while {[lassign [p] more p a b c;set more]} {

incr count

incr primitive $p

}

list $count $primitive

}

lassign [countPythagoreanTriples 100] count primitive

puts "$count triples, $primitive primitive"</lang>