tasks a-s

Task/Pythagorean-triples/Tcl/pythagorean-triples.tcl

@@ -0,0 +1,25 @@
+proc countPythagoreanTriples {limit} {
+    lappend q 3 4 5
+    set idx [set count [set prim 0]]
+    while {$idx < [llength $q]} {
+	set a [lindex $q $idx]
+	set b [lindex $q [incr idx]]
+	set c [lindex $q [incr idx]]
+	incr idx
+	if {$a + $b + $c <= $limit} {
+	    incr prim
+	    for {set i 1} {$i*$a+$i*$b+$i*$c <= $limit} {incr i} {
+		incr count
+	    }
+	    lappend q \
+		[expr {$a + 2*($c-$b)}] [expr {2*($a+$c) - $b}] [expr {2*($a-$b) + 3*$c}] \
+		[expr {$a + 2*($b+$c)}] [expr {2*($a+$c) + $b}] [expr {2*($a+$b) + 3*$c}] \
+		[expr {2*($b+$c) - $a}] [expr {2*($c-$a) + $b}] [expr {2*($b-$a) + 3*$c}]
+	}
+    }
+    return [list $count $prim]
+}
+for {set i 10} {$i <= 10000000} {set i [expr {$i*10}]} {
+    lassign [countPythagoreanTriples $i] count primitive
+    puts "perimeter limit $i => $count triples, $primitive primitive"
+}