langs a-z

Task/Least-common-multiple/UNIX-Shell/least-common-multiple-1.sh

@@ -0,0 +1,21 @@
+gcd() {
+	# Calculate $1 % $2 until $2 becomes zero.
+	until test 0 -eq "$2"; do
+		# Parallel assignment: set -- 1 2
+		set -- "$2" "`expr "$1" % "$2"`"
+	done
+
+	# Echo absolute value of $1.
+	test 0 -gt "$1" && set -- "`expr 0 - "$1"`"
+	echo "$1"
+}
+
+lcm() {
+	set -- "$1" "$2" "`gcd "$1" "$2"`"
+	set -- "`expr "$1" \* "$2" / "$3"`"
+	test 0 -gt "$1" && set -- "`expr 0 - "$1"`"
+	echo "$1"
+}
+
+lcm 30 -42
+# => 210

Task/Least-common-multiple/UNIX-Shell/least-common-multiple-2.sh

@@ -0,0 +1,24 @@
+alias gcd eval \''set gcd_args=( \!*:q )	\\
+	@ gcd_u=$gcd_args[2]			\\
+	@ gcd_v=$gcd_args[3]			\\
+	while ( $gcd_v != 0 )			\\
+		@ gcd_t = $gcd_u % $gcd_v	\\
+		@ gcd_u = $gcd_v		\\
+		@ gcd_v = $gcd_t		\\
+	end					\\
+	if ( $gcd_u < 0 ) @ gcd_u = - $gcd_u	\\
+	@ $gcd_args[1]=$gcd_u			\\
+'\'
+
+alias lcm eval \''set lcm_args=( \!*:q )	\\
+	@ lcm_m = $lcm_args[2]			\\
+	@ lcm_n = $lcm_args[3]			\\
+	gcd lcm_d $lcm_m $lcm_n			\\
+	@ lcm_r = ( $lcm_m * $lcm_n ) / $lcm_d	\\
+	if ( $lcm_r < 0 ) @ lcm_r = - $lcm_r	\\
+	@ $lcm_args[1] = $lcm_r			\\
+'\'
+
+lcm result 30 -42
+echo $result
+# => 210