ocaml: phase 5.1 palindrome_part.ml baseline (min cuts "aabba" = 1)

Two-phase palindrome-partition DP for the minimum-cuts variant:

  Phase 1: is_pal[i][j] palindrome table via length-major fill
           (single chars, then pairs, then expand inward).

  Phase 2: cuts[i] = 0 if s[0..i] is itself a palindrome,
                  = min over j of (cuts[j-1] + 1)
                    where s[j..i] is a palindrome.

  min_cut "aabba" = 1   ("a" | "abba")

Tests two sequential 2D DPs sharing the same is_pal matrix,
inline begin/end branches inside the length-major fill, mixed
bool and int 2D arrays.

181 baseline programs total.

plans/ocaml-on-sx.md

@@ -407,6 +407,16 @@ _Newest first._
   binary search tree (`type 'a tree = Leaf | Node of 'a * 'a tree *
   'a tree`) with insert + in-order traversal. Tests parametric ADT,
   recursive match, List.append, List.fold_left.
+- 2026-05-11 Phase 5.1 — palindrome_part.ml baseline (minimum
+  palindrome-partition cuts in "aabba" = 1). Two-phase DP:
+    1) `is_pal.(i).(j)` table via length-major iteration.
+    2) `cuts.(i)` = min cuts for prefix s[0..i]; if s[0..i] itself
+       is a palindrome, 0; else min over j of (cuts.(j-1) + 1)
+       where s[j..i] is a palindrome.
+  For "aabba" the optimal partition is "a" | "abba" = 1 cut.
+  Tests sequential 2D DP passes sharing the same `is_pal` matrix,
+  inline `if/else begin/end` blocks under length-major fill, mixed
+  bool and int 2D arrays. 181 baseline programs total.
 - 2026-05-11 Phase 5.1 — island_count.ml baseline (count 4-connected
   components of 1-cells in a 6×7 grid = 5). DFS flood from every
   unvisited 1-cell. Counted islands: