PAIP original programs on search is modernized here.
The aim of search.lisp is to teach some of search technique in AI, Depth First Search, Breadth First Search, Best First Search, and A* (pronounced [eI] star) algorithm.
The example adopted here is finding a flight route from Boston to San Francisco by a small airplane that can fly only 1000 km on one flight. This example is roughly same as PAIP, but
the exact lat&long data of actual airport location was prepared rather than city data as follows.
(defparameter *cities*
'((Atlanta ATL 33.636667 -84.428056)
(Los-Angeles LAX 33.9425 -118.408056)
(Boston BOS 42.363056 -71.006389)
(Memphis MEM 35.0425 -89.976667)
(Chicago ORD 41.978611 -87.904722)
(New-York LGA 40.77725 -73.872611)
(Denver DEN 39.861656 -104.673178)
(Oklahoma-City OKC 35.393056 -97.600833)
(Eugene EUG 44.123056 -123.218611)
(Pittsburgh PIT 40.491389 -80.232778)
(Flagstaff FLG 35.140278 -111.669167)
(Quebec YQB 46.791111 -71.393333)
(Grand-Jct GJT 39.1225 -108.526667)
(Reno RNO 39.499167 -119.768056)
(Houston IAH 29.984444 -95.341389)
(San-Francisco SFO 37.618889 -122.375)
(Indianapolis IND 39.717222 -86.294444)
(Tampa TPA 27.975556 -82.533333)
(Jacksonville JAX 30.494167 -81.687778)
(Victoria YYJ 48.647222 -123.425833)
(Kansas-City MCI 39.2975 -94.713889)
(Wilmington ILM 34.270556 -77.9025)))