From 98501dec8b2f665e768f13b459e5b0c594d69566 Mon Sep 17 00:00:00 2001
From: Alan Daniels <alan.daniels10@gmail.com>
Date: Sat, 13 Dec 2025 13:42:48 +1100
Subject: [PATCH] day 5 part 1

---
 05a.lisp      | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++
 05example.txt | 11 ++++++++++
 flake.nix     |  2 +-
 3 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100644 05a.lisp
 create mode 100644 05example.txt

diff --git a/05a.lisp b/05a.lisp
new file mode 100644
index 0000000..e08fdbc
--- /dev/null
+++ b/05a.lisp
@@ -0,0 +1,59 @@
+(load (sb-ext:posix-getenv "ASDF"))
+(asdf:load-system 'str)
+(asdf:load-system 'alexandria)
+
+(defun parse-line (line)
+  (str:match line
+             ((first "-" last)
+              (cons (parse-integer first) (parse-integer last)))
+             ((test)
+              (parse-integer test))
+             )
+  )
+(parse-line "5-15")
+(parse-line "6")
+
+(defun in-set-last (item setp)
+  (let ((first (car setp)) (last (cdr setp)))
+    (if (and (>= item first) (<= item last))
+      (+ last 1))))
+(defun in-set-first (item setp)
+  (let ((first (car setp)) (last (cdr setp)))
+    (if (and (>= item first) (<= item last))
+      (- first 1))))
+(in-set-first 5 (cons 5 15))
+
+(defun in-superset (item superset test)
+  (loop for setp in superset
+        when (funcall test item setp)
+        return (funcall test item setp))
+  )
+(in-superset 10 (list (parse-line "5-15") (parse-line "20-30")) #'in-set-first)
+(in-superset 10 (list (parse-line "5-15") (parse-line "20-30")) #'in-set-last)
+
+(defun set-transform (set superset)
+  (let ((first (car set)) (last (cdr set)))
+    (setq first (or (in-superset first superset #'in-set-last) first))
+    (setq last (or (in-superset last superset #'in-set-first) last))
+    (if (< first last)
+      (cons first last))))
+(set-transform (cons 14 115) (list (cons 5 15) (cons 20 30)))
+
+(defun count-fresh-ingredients (filename)
+  (let ((superset ())
+        (fresh-count 0))
+    (loop for line in (str:lines (str:from-file filename) :omit-nulls t)
+          do (let ((parsed (parse-line line)))
+               (if (consp parsed)
+                 ; consp
+                 (alexandria:if-let (parsed (set-transform parsed superset))
+                           (setf superset (push parsed superset)))
+                 ; integerp
+                 (if (in-superset parsed superset #'in-set-last) (setq fresh-count (+ fresh-count 1)))
+                 )))
+    ;; (print superset)
+    fresh-count))
+
+(count-fresh-ingredients "05example.txt")
+
+(count-fresh-ingredients "05data.txt")
diff --git a/05example.txt b/05example.txt
new file mode 100644
index 0000000..2e9078d
--- /dev/null
+++ b/05example.txt
@@ -0,0 +1,11 @@
+3-5
+10-14
+16-20
+12-18
+
+1
+5
+8
+11
+17
+32
diff --git a/flake.nix b/flake.nix
index 079157b..d3de5ac 100644
--- a/flake.nix
+++ b/flake.nix
@@ -23,7 +23,7 @@
         default = pkgs.mkShellNoCC {
           packages = with pkgs; [
             shellcheck
-            (sbcl.withPackages (ps: [ps.str ps.cl-heap]))
+            (sbcl.withPackages (ps: [ps.str ps.cl-heap ps.alexandria]))
           ];
         };
       }