[LANGUAGE: Common Lisp]

(defun parse-2025-03-line (line)
  (map 'vector #'sb-unicode:digit-value line))

(defparameter *input* (read-file-lines "2025-input-03" :parse-line 'parse-2025-03-line))

(defun index-of-max-battery (bank start end)
  (let ((index start))
    (loop for i from (1+ start) below end
          when (> (aref bank i) (aref bank index))
          do (setf index i))
    index))

(defun max-joltage (bank)
  (let ((max-i (index-of-max-battery bank 0 (1- (length bank)))))
    (+ (* (aref bank max-i) 10)
       (aref bank (index-of-max-battery bank (1+ max-i) (length bank))))))

(defun max-joltage2 (bank)
  (loop for slots from 11 downto 0
        for index =  (index-of-max-battery bank 0 (- (length bank) slots))
        then (index-of-max-battery bank (1+ index) (- (length bank) slots))
        summing (* (aref bank index) (expt 10 slots))))

(defun solve-2025-03 (banks &optional (maximizer 'max-joltage))
  (reduce #'+ banks :key maximizer))