From 93b8ae46207cf29660fb3c21d34dc45ee872c670 Mon Sep 17 00:00:00 2001
From: Aryadev Chavali <aryadev@aryadevchavali.com>
Date: Thu, 13 Jul 2023 15:33:49 +0100
Subject: (2022)-deleted puzzle files

I think I did this by accident, check out
https://git.aryadevchavali.com/advent-of-code/ for my actual advent of
code runs.
---
 2022/puzzle-5.lisp | 148 -----------------------------------------------------
 1 file changed, 148 deletions(-)
 delete mode 100644 2022/puzzle-5.lisp

(limited to '2022/puzzle-5.lisp')

diff --git a/2022/puzzle-5.lisp b/2022/puzzle-5.lisp
deleted file mode 100644
index 09be798..0000000
--- a/2022/puzzle-5.lisp
+++ /dev/null
@@ -1,148 +0,0 @@
-(defvar input (uiop:read-file-string "2022/5-input"))
-
-;; When we get two newlines, it means the end of the initial state and
-;; the start of instructions
-(defvar parse-separator (search (format nil "~%~%") input))
-(defvar initial-state
-  (with-input-from-string (s (subseq input 0 parse-separator))
-    (loop
-      for line = (read-line s nil)
-      until (null line)
-      collect line)))
-
-;; the last number, indicating the number of stacks
-(defparameter n-stacks (let ((str (car (last initial-state))))
-                         (parse-integer (subseq str (- (length str) 1)))))
-
-(defun default-state ()
-  (loop for i from 1 to n-stacks
-        collect nil))
-
-(defvar state
-  (default-state))
-
-#|
-conjecture: the nth stack, if it has an entry, has '[' beginning at index 4n;
-
-base case: the 0th stack must begin at index 0 (if at all)
-
-intuition: next stack must start at 0 + 2 (for the stack info) +
-1 (for whitespace) + 1 so 4.
-
-inductive hypothesis: for the kth stack [ begins at 4k
-
-proof of induction claim: from 4k we have the following:
-4k+1: symbol
-4k+2: ]
-4k+3: whitespace
-4k+4: data for the (k+1 stack)
-
-Immediately 4k+4 = 4(k+1) so by principle of induction we have the
-conjecture.  QED.
-
-This gives us all the information we need to make a parser: check
-every position and see if it has a [ char.  If so then parse the data
-and insert into the index/4th stack!|#
-
-(defun parse-initial-state ()
-  (loop
-    ;; don't want to parse the last line
-    for j in (remove (car (last initial-state)) initial-state)
-    do
-       (loop
-         for i from 0
-         for c across j
-         do
-            (if (char= c #\[)
-                (let ((ind (/ i 4))
-                      (sym (subseq j (+ i 1) (+ i 2))))
-                  (setf (nth ind state) (append (nth ind state) (list sym))))))))
-
-
-;; Now we have the initial memory layout, we need to parse program code.
-
-;; + 2 because two newlines
-(defvar instructions-str (subseq input (+ 2 parse-separator)))
-
-#| Each command is of the following: move ~n from ~a to ~b.
-
-~n is some natural number of crates, ~a is the stack from which we
-are taking them and ~b is the stack we are adding them to.  Let's
-define this operation first!  |#
-
-(defun move-crates (n a b)
-  "Take N number of crates from stack at position A to stack at position B"
-  (let ((stack-a (nth a state))
-        (stack-b (nth b state)))
-    (if (= n 0)
-        nil
-        (progn
-          ;; Pop the first element off the stack
-          (setf (nth a state) (cdr stack-a))
-          ;; Then cons that onto b
-          (setf (nth b state) (cons (car stack-a) stack-b))
-          ;; Recur
-          (move-crates (- n 1) a b)))))
-
-(defun parse-instruction-str (instruction)
-  "Given INSTRUCTION of form \"move n from a to b\", return (n (a - 1) (b - 1))"
-  (let ((first (search "move " instruction))
-        (second (search "from " instruction))
-        (third (search "to " instruction)))
-    (list
-     (parse-integer (subseq instruction (+ 5 first) (- second 1)))
-     ;; Input assumes crates start at 1, but we need it to start at 0
-     (- (parse-integer (subseq instruction (+ 5 second) (- third 1))) 1)
-     (- (parse-integer (subseq instruction (+ 3 third))) 1))))
-
-(defun perform-instructions (instructions)
-  (with-input-from-string (s instructions)
-    (loop
-      for line = (read-line s nil)
-      until (null line)
-      collect
-      ;; Parse each instruction then move the crates!
-      (destructuring-bind (n a b) (parse-instruction-str line)
-        (move-crates n a b)))))
-
-(defun first-round ()
-  (setq state (default-state))
-  (parse-initial-state)
-  (perform-instructions instructions-str)
-  (let ((ret (mapcar #'car state)))
-    (setq state (default-state))
-    (reduce (lambda (s1 s2) (concatenate 'string s1 s2)) ret)))
-
-;; Round 2 is pretty simple: the move-crates algorithm is overhauled
-;; to keep movements "in-order".  Thankfully I already implemented
-;; this by accident when implementing move-crates, so easy!
-
-(defun move-crates-2 (n a b)
-  (let ((stack-a (nth a state))
-        (stack-b (nth b state)))
-    (setf (nth b state)
-          (append (loop for i from 1 to n
-                        for j in stack-a
-                        collect j)
-                  stack-b))
-    (dotimes (i n)
-      (setf stack-a (cdr stack-a)))
-    (setf (nth a state) stack-a)))
-
-(defun perform-instructions-2 (instructions)
-  (with-input-from-string (s instructions)
-    (loop
-      for line = (read-line s nil)
-      until (null line)
-      collect
-      ;; Parse each instruction then move the crates!
-      (destructuring-bind (n a b) (parse-instruction-str line)
-        (move-crates-2 n a b)))))
-
-(defun second-round ()
-  (setq state (default-state))
-  (parse-initial-state)
-  (perform-instructions-2 instructions-str)
-  (let ((ret (mapcar #'car state)))
-    (setq state (default-state))
-    (reduce (lambda (s1 s2) (concatenate 'string s1 s2)) ret)))
-- 
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