Merge branch 'develop'

1 files changed, 55 insertions, 0 deletions

diff --git a/comparison/SML/msort-260000.sml b/comparison/SML/msort-260000.sml
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+(* https://stackoverflow.com/questions/25839939/understanding-merge-sort-in-ml *)
+
+fun split [] = ([], [])
+  | split [a] = ([a], [])
+  | split (a::b::cs) =
+    let
+	val (m,n) = split cs
+    in
+	(a::m, b::n)
+    end;
+
+fun merge ([], ys) = ys
+  | merge (xs, []) = xs
+  | merge (x::xs, y::ys) =
+    if x<y then
+	x::merge(xs, y::ys)
+    else
+	y::merge(x::xs, ys);
+
+fun msort [] = []
+  | msort [a] = [a]
+  | msort [a,b] = if a<b then [a,b] else [b,a]
+  | msort xs =
+    let
+	val (m,n) = split xs;
+    in
+	merge (msort m, msort n)
+    end;
+
+
+(* Creates a random list *)
+local 
+    val nextInt = Random.randRange(1,10000);
+    val r = Random.rand(1,1);
+in
+  fun mkRandList 0 = []
+    | mkRandList n = (nextInt r)::(mkRandList (n-1))
+end;
+
+
+(* Validation checks *)
+fun validation [] = true
+  | validation (x::xs) =
+    let fun validation_cons x [] = true
+	  | validation_cons x (y::ys) =
+	    if x<=y then validation_cons y ys
+	    else false
+    in
+	validation_cons x xs
+    end;
+
+
+(* Main *)
+validation(msort (mkRandList 260000));
+