Data commit

Task/Maximum-triangle-path-sum/Common-Lisp/maximum-triangle-path-sum.lisp

@@ -0,0 +1,24 @@
+(defun find-max-path-sum (s)
+  (let ((triangle (loop for line = (read-line s NIL NIL)
+                        while line
+                        collect (with-input-from-string (str line)
+                                  (loop for n = (read str NIL NIL)
+                                        while n
+                                        collect n)))))
+    (flet ((get-max-of-pairs (xs)
+             (maplist (lambda (ys)
+                        (and (cdr ys) (max (car ys) (cadr ys))))
+                      xs)))
+      (car (reduce (lambda (xs ys)
+                     (mapcar #'+ (get-max-of-pairs xs) ys))
+                   (reverse triangle))))))
+
+(defparameter *small-triangle*
+  "    55
+     94 48
+    95 30 96
+  77 71 26 67")
+(format T "~a~%" (with-input-from-string (s *small-triangle*)
+                   (find-max-path-sum s)))
+(format T "~a~%" (with-open-file (f "triangle.txt")
+                   (find-max-path-sum f)))