[2022/D08] Solved both tasks from today

1 files changed, 51 insertions, 0 deletions

diff --git a/2022/Day08/part-two.cl b/2022/Day08/part-two.cl
new file mode 100644
index 0000000..f20ffe5
--- /dev/null
+++ b/2022/Day08/part-two.cl
@@ -0,0 +1,51 @@
+
+;;; https://gitlab.com/Syndamia/senzill
+(require :senzill)
+(use-package :senzill.math)
+(use-package :senzill.collections)
+(use-package :senzill.io)
+
+(ask-for-stream (prog-input)
+  (let ((forest '()))
+    (doread-lines (inpt :read-line-options (prog-input NIL))
+                  (push-back (map 'list
+                                  (lambda (x) (cons x 1)) ; Each tree is a (cons) pair of (<TREE_HEIGHT> . <SCENIC_SCORE>)
+                                  (integer-to-list (parse-integer inpt)
+                                                   :min-length (length (first forest)))) ; Doesn't handle if very first digit(s) is zero
+                             forest))
+
+    (defun loop-on-row (row)
+      (loop for col on row
+            maximize (car (first col)) into max-height
+            while (cdr col) 
+            do
+            (*= (cdr (first col))
+                ;;; Counts seen trees on the right of the current tree
+                (loop for seen on (cdr col)
+                      count T into result
+                      while (and col (> (car (first col)) (car (first seen))))
+                      finally (return result)))
+            finally (setf (cdr (first col)) 0))) ; Last tree doesn't see any trees
+
+    ;;; Checks every row
+    (loop for row in forest
+          do
+          ;; Iterate from left to right
+          (loop-on-row row)
+          ;; Iterate from right to left
+          (loop-on-row (reverse row)))
+
+    ;;; Checks every column
+    (loop for i from 0 to (- (length (first forest)) 1)
+          for col = (loop for row in forest
+                          collect (nth i row))
+          do
+          ;; Iterate top to bottom
+          (loop-on-row col)
+          ;; Iterate bottom to top
+          (loop-on-row (reverse col)))
+
+    (loop for row in forest
+          maximize (loop for tree in row
+                         maximize (cdr tree)) into result
+          finally (print result))))