- Added more guest contributions by Laurent Rosenfeld.

4 files changed, 126 insertions, 0 deletions

diff --git a/challenge-175/laurent-rosenfeld/dart/ch-2.dart b/challenge-175/laurent-rosenfeld/dart/ch-2.dart
new file mode 100644
index 0000000000..475955d7f3
--- /dev/null
+++ b/challenge-175/laurent-rosenfeld/dart/ch-2.dart
@@ -0,0 +1,29 @@
+import "dart:io";
+
+var cache = List<int>.filled(10000, 0, growable: true);
+
+void main() {
+    cache[0] = 0;
+    var count = 0;
+    var i = 1;
+    while (count < 20) {
+        if (is_perfect_totient(i)) {
+            stdout.write("$i ");
+            count++;
+        }
+        i++;
+    }
+    print(" ");
+}
+
+bool is_perfect_totient(n) {
+    var tot = 0;
+    for (int i = 1; i < n; i++ ) {
+       if (i.gcd(n) == 1) {
+            tot++;
+        }
+    }
+    int sum = tot + cache[tot];
+    cache[n] = sum;
+    return n == sum;
+}
diff --git a/challenge-175/laurent-rosenfeld/ruby/ch-2.rb b/challenge-175/laurent-rosenfeld/ruby/ch-2.rb
new file mode 100644
index 0000000000..879107e1c5
--- /dev/null
+++ b/challenge-175/laurent-rosenfeld/ruby/ch-2.rb
@@ -0,0 +1,24 @@
+$cache = Array.new(10000, 0) # global variables require $
+
+def is_perfect_totient(n)
+    tot = 0
+    for i in 1..(n - 1)
+        if n.gcd(i) == 1
+            tot += 1
+        end
+    end
+    sum = tot + $cache[tot]
+    $cache[n] = sum;
+    return sum == n
+end
+
+i = 1
+count = 0
+while count < 20
+    if is_perfect_totient(i)
+        printf("%d ", i)
+        count += 1
+    end
+    i += 1
+end
+print("\n")
diff --git a/challenge-175/laurent-rosenfeld/scala/ch-2.scala b/challenge-175/laurent-rosenfeld/scala/ch-2.scala
new file mode 100644
index 0000000000..bbd7c7da3a
--- /dev/null
+++ b/challenge-175/laurent-rosenfeld/scala/ch-2.scala
@@ -0,0 +1,37 @@
+object PerfectTotient extends App {
+
+  var cache = new Array[Int](10000)
+
+  def gcd(a: Int, b: Int): Int = {
+    var (i, j) = (a, b)
+    while (j > 0) {
+      var t = i
+      i = j
+      j = t % j
+    }
+    return i
+  }
+
+  def is_perfect_totient(n: Int): Boolean = {
+    var tot = 0
+    for (i <- 1 to (n - 1)) {
+      if (gcd(n, i) == 1) {
+        tot += 1
+      }
+    }
+    val sum = tot + cache(tot)
+    cache(n) = sum
+    return n == sum
+  }
+
+  var i = 1
+  var count = 0
+  while (count < 20) {
+    if (is_perfect_totient(i)) {
+      count += 1
+      printf("%d ", i)
+    }
+    i += 1
+  }
+  println("")
+}
diff --git a/challenge-175/laurent-rosenfeld/tcl/ch-2.tcl b/challenge-175/laurent-rosenfeld/tcl/ch-2.tcl
new file mode 100644
index 0000000000..92aaa64301
--- /dev/null
+++ b/challenge-175/laurent-rosenfeld/tcl/ch-2.tcl
@@ -0,0 +1,36 @@
+array set cache {}
+
+set cache(0) 0
+
+proc gcd {i j} {
+   while {$j != 0} {
+      set t [expr {$i % $j}]
+      set i $j
+      set j $t
+   }
+   return $i
+}
+
+proc is_perfect_totient {n} {
+    global cache
+    set tot 0
+    for {set i 1} {$i < $n} {incr i} {
+        if [ expr [gcd $i $n] == 1 ] {
+            incr tot
+        }
+    }
+    set sum [expr $tot + $cache($tot)]
+    set cache($n) $sum
+    return [ expr $n == $sum ? 1 : 0]
+}
+
+set i 1
+set count 0
+while { $count < 20 } {
+    if [ is_perfect_totient $i ] {
+        puts -nonewline  "${i} "
+        incr count
+    }
+    incr i
+}
+puts ""