Data commit

Task/Sorting-algorithms-Merge-sort/Maxima/sorting-algorithms-merge-sort.maxima

@@ -0,0 +1,22 @@
+merge(a, b) := block(
+   [c: [ ], i: 1, j: 1, p: length(a), q: length(b)],
+   while i <= p and j <= q do (
+      if a[i] < b[j] then (
+         c: endcons(a[i], c),
+         i: i + 1
+      ) else (
+         c: endcons(b[j], c),
+         j: j + 1
+      )
+   ),
+   if i > p then append(c, rest(b, j - 1)) else append(c, rest(a, i - 1))
+)$
+
+mergesort(u) := block(
+   [n: length(u), k, a, b],
+   if n <= 1 then u else (
+      a: rest(u, k: quotient(n, 2)),
+      b: rest(u, k - n),
+      merge(mergesort(a), mergesort(b))
+   )
+)$