- Added more guest contributions by Laurent Rosenfeld.

7 files changed, 145 insertions, 0 deletions

diff --git a/challenge-146/laurent-rosenfeld/awk/ch-2.awk b/challenge-146/laurent-rosenfeld/awk/ch-2.awk
new file mode 100644
index 0000000000..5bb11d3c98
--- /dev/null
+++ b/challenge-146/laurent-rosenfeld/awk/ch-2.awk
@@ -0,0 +1,26 @@
+# Run for example as:
+# echo ' 5/2
+# 2/5
+# 3/5' | awk -f fraction-tree.awk
+function parent()
+{
+    if (a < b) {
+        b = b - a
+    } else {
+        a = a - b
+    }
+}
+BEGIN {
+    a = 0
+    b = 0
+    FS = "/"
+}
+{
+    a = $1
+    b = $2
+    printf "Node = %d/%d: ", a, b
+    parent()
+    printf "Parent = %d/%d; ", a, b
+    parent()
+    printf "Grand-parent = %d/%d\n", a, b
+}
diff --git a/challenge-146/laurent-rosenfeld/c/ch-2.c b/challenge-146/laurent-rosenfeld/c/ch-2.c
new file mode 100644
index 0000000000..e36e91bc3b
--- /dev/null
+++ b/challenge-146/laurent-rosenfeld/c/ch-2.c
@@ -0,0 +1,21 @@
+#include <STDIO>
+void parent(int *a, int *b) {
+    if (*a < *b) {
+        *b -= *a;
+    } else {
+        *a -= *b;
+    }
+}
+
+int main (void) {
+    int num, denom;
+
+    while (scanf ("%d/%d", &num, &denom) == 2) {
+        printf("%d/%d - ", num, denom);
+        parent(&num, &denom);
+        printf("Parent: %d/%d - ", num, denom);
+        parent(&num, &denom);
+        printf("Grand-parent: %d/%d \n", num, denom);
+    }
+    return (0);
+}
diff --git a/challenge-146/laurent-rosenfeld/julia/ch-1.jl b/challenge-146/laurent-rosenfeld/julia/ch-1.jl
new file mode 100644
index 0000000000..62091968d1
--- /dev/null
+++ b/challenge-146/laurent-rosenfeld/julia/ch-1.jl
@@ -0,0 +1,24 @@
+function getprimes(max)
+    primes = [2, 3, 5]
+    count = 3
+    candidate = 5
+    while (count <= max)
+        candidate += 2
+        not_prime = false
+        sq_cand = sqrt(candidate)
+        for i in primes
+            if (candidate % i == 0)
+                not_prime = true
+                break
+            end
+            i > max && break
+        end
+        not_prime && continue
+        push!(primes, candidate)
+        count += 1
+    end
+    return primes[max] # Julia arrays start with index 1
+end
+
+p = getprimes(10001)
+println(p)
diff --git a/challenge-146/laurent-rosenfeld/kotlin/ch-2.kt b/challenge-146/laurent-rosenfeld/kotlin/ch-2.kt
new file mode 100644
index 0000000000..4b7736b070
--- /dev/null
+++ b/challenge-146/laurent-rosenfeld/kotlin/ch-2.kt
@@ -0,0 +1,19 @@
+fun find_parent(pair: IntArray): IntArray {
+    val num = pair[0]
+    val denom = pair[1]
+    return if (num < denom) intArrayOf(num, denom - num) else intArrayOf(num - denom, denom)
+}
+
+fun n2str (pair: IntArray): String {
+    return "${pair[0]}/${pair[1]}"
+}
+
+fun main() {
+val tests  = arrayOf(intArrayOf(5,2), intArrayOf(2,5), intArrayOf(3,4))
+    for (test in tests) {
+        val parent = find_parent(test)
+        val gd_parent = find_parent(parent)
+        print(n2str(test) + " - Parent: " + n2str(parent))
+        println(" - Grand-parent: " + n2str(gd_parent))
+    }
+}
diff --git a/challenge-146/laurent-rosenfeld/lua/ch-2.lua b/challenge-146/laurent-rosenfeld/lua/ch-2.lua
new file mode 100644
index 0000000000..bb1e3c546c
--- /dev/null
+++ b/challenge-146/laurent-rosenfeld/lua/ch-2.lua
@@ -0,0 +1,22 @@
+-- For a node `x/y` with a fraction less than 1, the parent is `x/(y-x)`;
+-- For a node `x/y` with a fraction larger than 1, the parent is `(x-y)/x`.
+
+local function get_parent(pair)
+    num = pair[1]
+    denom = pair[2]
+    -- no ternary operator in Lua, we can simulate it with and / or:
+    return num < denom and {num, denom - num} or {num - denom, denom}
+end
+
+local function to_str(pair)
+    -- return pair[1] .. "/" .. pair[2]
+    return table.concat(pair, "/")
+end
+
+local tests = { {5, 2}, {2, 5}, {3, 4}, {3,5} }
+for _, test in pairs(tests) do
+    parent = get_parent(test)
+    gd_parent = get_parent(parent)
+    print("Node " .. to_str(test) .. " - Parent: " .. to_str(parent)
+        .. " - Grand-Parent: " .. to_str(gd_parent))
+end
diff --git a/challenge-146/laurent-rosenfeld/ruby/ch-2.rb b/challenge-146/laurent-rosenfeld/ruby/ch-2.rb
new file mode 100644
index 0000000000..4a6b896394
--- /dev/null
+++ b/challenge-146/laurent-rosenfeld/ruby/ch-2.rb
@@ -0,0 +1,15 @@
+# For a node `x/y` with a fraction less than 1, the parent is `x/(y-x)`;
+# For a node `x/y` with a fraction larger than 1, the parent is `(x-y)/x`.
+
+def get_parent (pair)
+    num = pair[0]
+    denom = pair[1]
+  return num < denom ? [num, denom - num] : [num - denom, denom];
+end
+
+tests = [ [5, 2], [2, 5], [3, 4], [3,5] ]
+for test in tests
+    parent = get_parent(test)
+    gd_parent = get_parent(parent)
+    print("Node #{test} - Parent: #{parent} - Grand-Parent: #{gd_parent}\n")
+end
diff --git a/challenge-146/laurent-rosenfeld/scala/ch-2.scala b/challenge-146/laurent-rosenfeld/scala/ch-2.scala
new file mode 100644
index 0000000000..712b686830
--- /dev/null
+++ b/challenge-146/laurent-rosenfeld/scala/ch-2.scala
@@ -0,0 +1,18 @@
+object fraction_tree extends App {
+
+  def findParent(pair: List[Int]): List[Int] = {
+    val num = pair(0)
+    val denom = pair(1)
+    return if (num < denom) List(num, denom - num) else List(num - denom, denom)
+  }
+  def n2str(pair: List[Int]): String = {
+    return s"${pair(0)}" + "/" + s"${pair(1)}"
+  }
+
+  val tests: List[List[Int]] = List(List(5, 2), List(2, 5), List(3, 4))
+  for (test <- tests) {
+    val parent = findParent(test)
+    val gd_parent = findParent(parent)
+    println(n2str(test) + " - Parent: " + n2str(parent) + " - Grand-parent: " + n2str(gd_parent))
+  }
+}