September Morn Update

Task/Combinations/Elena/combinations.elena

@@ -1,22 +1,22 @@
-import system'routines.
-import extensions.
-import extensions'routines.
+import system'routines;
+import extensions;
+import extensions'routines;
 
-const int M = 3.
-const int N = 5.
+const int M = 3;
+const int N = 5;
 
-numbers = (:anN)
-[
-    ^ Array new(anN); populate(:n)<int>( n )
-].
+Numbers(n)
+{
+    ^ Array.allocate(n).populate:(int n => n)
+}
 
-public program =
-[
-    var aNumbers := numbers(N).
-    Combinator new:M of:aNumbers; forEach(:aRow)
-    [
-        console printLine(aRow toLiteral)
-    ].
+public program()
+{
+    var numbers := Numbers(N);
+    Combinator.new(M, numbers).forEach:(row)
+    {
+        console.printLine(row.toString())
+    };
 
-    console readChar.
-].
+    console.readChar()
+}

Task/Combinations/Nim/combinations-2.nim

@@ -0,0 +1,16 @@
+iterator Combinations(m: int, n: int): seq[int] =
+    var result = newSeq[int](m)
+    var stack = initDeque[int]()
+    stack.addLast 0
+    while len(stack) > 0:
+        var index = len(stack) - 1
+        var value = stack.popLast()
+        while value < n:
+            value = value + 1
+            result[index] = value
+            index = index + 1
+            stack.addLast value
+
+            if index == m:
+                yield result
+                break

Task/Combinations/OCaml/combinations.ocaml

@@ -0,0 +1,15 @@
+let combinations m n =
+  let rec c = function
+    | (0,_) -> [[]]
+    | (_,0) -> []
+    | (p,q) -> List.append
+               (List.map (List.cons (n-q)) (c (p-1, q-1)))
+               (c (p , q-1))
+  in c (m , n)
+
+
+let () =
+  let rec print_list = function
+    | [] -> print_newline ()
+    | hd :: tl -> print_int hd ; print_string " "; print_list tl
+  in List.iter print_list (combinations 3 5)

Task/Combinations/OpenEdge-Progress/combinations.openedge

@@ -0,0 +1,19 @@
+define variable r as integer no-undo extent 3.
+define variable m as integer no-undo initial 5.
+define variable n as integer no-undo initial 3.
+define variable max_n as integer no-undo.
+
+max_n = m - n.
+
+function combinations returns logical (input pos as integer, input val as integer):
+  define variable i as integer no-undo.
+  do i = val to max_n:
+    r[pos] = pos + i.
+	if pos lt n then
+		combinations(pos + 1, i).
+	else
+	 	message r[1] - 1 r[2] - 1 r[3] - 1.
+  end.
+end function.
+
+combinations(1, 0).

Task/Combinations/Rust/combinations-2.rust

@@ -0,0 +1,62 @@
+struct Combo<T> {
+    data_len: usize,
+    chunk_len: usize,
+    min: usize,
+    mask: usize,
+    data: Vec<T>,
+}
+
+impl<T: Clone> Combo<T> {
+    fn new(chunk_len: i32, data: Vec<T>) -> Self {
+        let d_len = data.len();
+        let min = 2usize.pow(chunk_len as u32) - 1;
+        let max = 2usize.pow(d_len as u32) - 2usize.pow((d_len - chunk_len as usize) as u32);
+
+        Combo {
+            data_len: d_len,
+            chunk_len: chunk_len as usize,
+            min: min,
+            mask: max,
+            data: data,
+        }
+    }
+
+    fn get_chunk(&self) -> Vec<T> {
+        let b = format!("{:01$b}", self.mask, self.data_len);
+        b
+           .chars()
+           .enumerate()
+           .filter(|&(_, e)| e == '1')
+           .map(|(i, _)| self.data[i].clone())
+           .collect()
+    }
+}
+
+impl<T: Clone> Iterator for Combo<T> {
+    type Item = Vec<T>;
+    fn next(&mut self) -> Option<Self::Item> {
+        while self.mask >= self.min {
+            if self.mask.count_ones() == self.chunk_len as u32 {
+                let res = self.get_chunk();
+                self.mask -= 1;
+                return Some(res);
+            }
+            self.mask -= 1;
+        }
+        None
+    }
+}
+
+fn main() {
+    let v1 = vec![1, 2, 3, 4, 5];
+    let combo = Combo::new(3, v1);
+    for c in combo.into_iter() {
+        println!("{:?}", c);
+    }
+
+    let v2 = vec!("A", "B", "C", "D", "E");
+    let combo = Combo::new(3, v2);
+    for c in combo.into_iter() {
+        println!("{:?}", c);
+    }
+}

Task/Combinations/VBA/combinations-2.vba

@@ -0,0 +1,24 @@
+Private Sub comb(ByVal pool As Integer, ByVal needed As Integer, Optional ByVal done As Integer = 0, Optional ByVal chosen As Variant)
+    If needed = 0 Then  '-- got a full set
+        For Each x In chosen: Debug.Print x;: Next x
+        Debug.Print
+        Exit Sub
+    End If
+    If done + needed > pool Then Exit Sub '-- cannot fulfil
+    '-- get all combinations with and without the next item:
+    done = done + 1
+    Dim tmp As Variant
+    tmp = chosen
+    If IsMissing(chosen) Then
+        ReDim tmp(1)
+    Else
+        ReDim Preserve tmp(UBound(chosen) + 1)
+    End If
+    tmp(UBound(tmp)) = done
+    comb pool, needed - 1, done, tmp
+    comb pool, needed, done, chosen
+End Sub
+
+Public Sub main()
+    comb 5, 3
+End Sub