A-M baby

Task/Combinations/Factor/combinations-1.factor

@@ -0,0 +1,3 @@
+USING: math.combinatorics prettyprint ;
+
+5 iota 3 all-combinations .

Task/Combinations/Factor/combinations-2.factor

@@ -0,0 +1 @@
+{ "a" "b" "c" } 2 all-combinations .

Task/Combinations/GAP/combinations.gap

@@ -0,0 +1,6 @@
+# Built-in
+Combinations([1 .. n], m);
+
+Combinations([1 .. 5], 3);
+# [ [ 1, 2, 3 ], [ 1, 2, 4 ], [ 1, 2, 5 ], [ 1, 3, 4 ], [ 1, 3, 5 ],
+#   [ 1, 4, 5 ], [ 2, 3, 4 ], [ 2, 3, 5 ], [ 2, 4, 5 ], [ 3, 4, 5 ] ]

Task/Combinations/Groovy/combinations-1.groovy

@@ -0,0 +1,10 @@
+def comb
+comb = { m, list ->
+    def n = list.size()
+    m == 0 ?
+        [[]] :
+        (0..(n-m)).inject([]) { newlist, k ->
+            def sublist = (k+1 == n) ? [] : list[(k+1)..<n]
+            newlist += comb(m-1, sublist).collect { [list[k]] + it }
+        }
+}

Task/Combinations/Groovy/combinations-2.groovy

@@ -0,0 +1,3 @@
+def csny = [ "Crosby", "Stills", "Nash", "Young" ]
+println "Choose from ${csny}"
+(0..(csny.size())).each { i -> println "Choose ${i}:"; comb(i, csny).each { println it }; println() }

Task/Combinations/Groovy/combinations-3.groovy

@@ -0,0 +1 @@
+def comb0 = { m, n -> comb(m, (0..<n)) }

Task/Combinations/Groovy/combinations-4.groovy

@@ -0,0 +1,2 @@
+println "Choose out of 5 (zero-based):"
+(0..3).each { i -> println "Choose ${i}:"; comb0(i, 5).each { println it }; println() }

Task/Combinations/Groovy/combinations-5.groovy

@@ -0,0 +1 @@
+def comb1 = { m, n -> comb(m, (1..n)) }

Task/Combinations/Groovy/combinations-6.groovy

@@ -0,0 +1,2 @@
+println "Choose out of 5 (one-based):"
+(0..3).each { i -> println "Choose ${i}:"; comb1(i, 5).each { println it }; println() }

Task/Combinations/Icon/combinations-1.icon

@@ -0,0 +1,20 @@
+procedure main()
+return combinations(3,5,0)
+end
+
+procedure combinations(m,n,z)                      # demonstrate combinations
+/z := 1
+
+write(m," combinations of ",n," integers starting from ",z)
+every put(L := [], z to n - 1 + z by 1)            # generate list of n items from z
+write("Intial list\n",list2string(L))
+write("Combinations:")
+every write(list2string(lcomb(L,m)))
+end
+
+procedure list2string(L)                           # helper function
+every (s := "[") ||:= " " || (!L|"]")
+return s
+end
+
+link lists

Task/Combinations/Icon/combinations-2.icon

@@ -0,0 +1,8 @@
+procedure lcomb(L,i)			#: list combinations
+   local j
+
+   if i < 1 then fail
+   suspend if i = 1 then [!L]
+      else [L[j := 1 to *L - i + 1]] ||| lcomb(L[j + 1:0],i - 1)
+
+end

Task/Combinations/J/combinations-1.j

@@ -0,0 +1,5 @@
+comb1=: dyad define
+  c=. 1 {.~ - d=. 1+y-x
+  z=. i.1 0
+  for_j. (d-1+y)+/&i.d do. z=. (c#j) ,. z{~;(-c){.&.><i.{.c=. +/\.c end.
+)

Task/Combinations/J/combinations-2.j

@@ -0,0 +1,3 @@
+comb=: dyad define M.
+  if. (x>:y)+.0=x do. i.(x<:y),x else. (0,.x comb&.<: y),1+x comb y-1 end.
+)

Task/Combinations/Julia/combinations.julia

@@ -0,0 +1,13 @@
+julia> for i in @task combinations(1:5,3)
+println(i)
+end
+[1, 2, 3]
+[1, 2, 4]
+[1, 3, 4]
+[2, 3, 4]
+[1, 2, 5]
+[1, 3, 5]
+[2, 3, 5]
+[1, 4, 5]
+[2, 4, 5]
+[3, 4, 5]

Task/Combinations/Logo/combinations.logo

@@ -0,0 +1,7 @@
+to comb :n :list
+  if :n = 0 [output [[]]]
+  if empty? :list [output []]
+  output sentence map [sentence first :list ?] comb :n-1 bf :list ~
+                  comb :n bf :list
+end
+print comb 3 [0 1 2 3 4]

Task/Combinations/M4/combinations.m4

@@ -0,0 +1,26 @@
+divert(-1)
+define(`set',`define(`$1[$2]',`$3')')
+define(`get',`defn(`$1[$2]')')
+define(`setrange',`ifelse(`$3',`',$2,`define($1[$2],$3)`'setrange($1,
+   incr($2),shift(shift(shift($@))))')')
+define(`for',
+   `ifelse($#,0,``$0'',
+   `ifelse(eval($2<=$3),1,
+   `pushdef(`$1',$2)$4`'popdef(`$1')$0(`$1',incr($2),$3,`$4')')')')
+define(`show',
+   `for(`k',0,decr($1),`get(a,k) ')')
+
+define(`chklim',
+   `ifelse(get(`a',$3),eval($2-($1-$3)),
+      `chklim($1,$2,decr($3))',
+      `set(`a',$3,incr(get(`a',$3)))`'for(`k',incr($3),decr($2),
+         `set(`a',k,incr(get(`a',decr(k))))')`'nextcomb($1,$2)')')
+define(`nextcomb',
+   `show($1)
+ifelse(eval(get(`a',0)<$2-$1),1,
+      `chklim($1,$2,decr($1))')')
+define(`comb',
+   `for(`j',0,decr($1),`set(`a',j,j)')`'nextcomb($1,$2)')
+divert
+
+comb(3,5)

Task/Combinations/Mathematica/combinations.mathematica

@@ -0,0 +1 @@
+combinations[n_Integer, m_Integer]/;m>= 0:=Union[Sort /@ Permutations[Range[0, n - 1], {m}]]

Task/Combinations/Maxima/combinations.maxima

@@ -0,0 +1,26 @@
+next_comb(n, p, a) := block(
+   [a: copylist(a), i: p],
+   if a[1] + p = n + 1 then return(und),
+   while a[i] - i >= n - p do i: i - 1,
+   a[i]: a[i] + 1,
+   for j from i + 1 thru p do a[j]: a[j - 1] + 1,
+   a
+)$
+
+combinations(n, p) := block(
+   [a: makelist(i, i, 1, p), v: [ ]],
+   while a # 'und do (v: endcons(a, v), a: next_comb(n, p, a)),
+   v
+)$
+
+combinations(5, 3);
+/* [[1, 2, 3],
+    [1, 2, 4],
+    [1, 2, 5],
+    [1, 3, 4],
+    [1, 3, 5],
+    [1, 4, 5],
+    [2, 3, 4],
+    [2, 3, 5],
+    [2, 4, 5],
+    [3, 4, 5]] */