1 files changed, 117 insertions, 0 deletions
diff --git a/AoC2023/day05/solver.lisp b/AoC2023/day05/solver.lisp
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+(ql:quickload '(fiveam str))
+
+(defparameter eg-input "seeds: 79 14 55 13
+
+seed-to-soil map:
+50 98 2
+52 50 48
+
+soil-to-fertilizer map:
+0 15 37
+37 52 2
+39 0 15
+
+fertilizer-to-water map:
+49 53 8
+0 11 42
+42 0 7
+57 7 4
+
+water-to-light map:
+88 18 7
+18 25 70
+
+light-to-temperature map:
+45 77 23
+81 45 19
+68 64 13
+
+temperature-to-humidity map:
+0 69 1
+1 0 69
+
+humidity-to-location map:
+60 56 37
+56 93 4")
+
+
+(defun translate (rules value)
+  (dolist (rule rules)
+    (destructuring-bind (dest source span) rule
+      (when (<= source value (+ source (1- span)))
+        (return-from translate (+ (- value source) dest)))))
+  value)
+
+(defun segment-translate (rules segments)
+  (let ((sorted-rules (sort rules #'< :key #'cadr)))
+    (mapcan
+     (lambda (segment)
+       (destructuring-bind (start . end) segment
+         (loop for (dest-start source-start span) in sorted-rules
+
+               )))
+     segments)))
+
+(sort '((50 98 2) (52 50 48)) #'< :key #'cadr)
+
+(fiveam:test parts
+  (let ((rules '((50 98 2) (52 50 48))))
+    (fiveam:is (= 9 (translate rules 9)))
+    (fiveam:is (= 61 (translate rules 59)))
+    (fiveam:is (= 51 (translate rules 99)))))
+
+(defun translator (translate-chain translator-rules)
+  (lambda (value)
+    (reduce
+     (lambda (acc fn)
+       (translate (gethash fn translator-rules) acc))
+     translate-chain
+     :initial-value value)))
+
+(defun parser (lines)
+  (let (seeds
+        maps-stack
+        (translators (make-hash-table)))
+    (dolist (line lines)
+      (cond
+        ((str:emptyp line))
+        ((str:starts-with? "seeds:" line)
+         (setf seeds
+               (mapcar #'parse-integer (cdr (str:split-omit-nulls #\Space line)))))
+        ((str:ends-with-p "map:" line)
+         (push (read-from-string line) maps-stack))
+        ((push (mapcar #'parse-integer (str:split-omit-nulls #\Space line))
+               (gethash (car maps-stack) translators)))))
+    (values (translator
+             (nreverse maps-stack)
+             translators)
+            seeds)))
+
+(defun solver1 (lines)
+  (multiple-value-bind (translator seeds) (parser lines)
+    (apply #'min (mapcar translator seeds))))
+
+
+(defun solver2 (lines)
+  (multiple-value-bind (translator seeds) (parser lines)
+    (loop for (start span) on seeds by #'cddr
+          minimize (loop for i from start below (+ start span)
+                         minimize (funcall translator i)))))
+
+(fiveam:test solutions
+  (fiveam:is
+   (= 35
+      (solver1
+       (uiop:split-string eg-input :separator '(#\Newline)))))
+  (fiveam:is
+   (= 46
+      (solver2
+       (uiop:split-string eg-input :separator '(#\Newline)))))
+  (fiveam:is
+   (= 662197086
+      (solver1
+       (uiop:read-file-lines "input"))))
+  (fiveam:is
+   (= 52510809
+      (solver2
+       (uiop:read-file-lines "input")))))