Sling Blade Runner IV

I've been doing some more work on my kōan, Sling Blade Runner. I've given up on the beam-stack search approach. I doubt it will improve results much. If any at all.

Instead I have spent some time on improving the extend method so that it can find more extensions. And it is becoming quite efficient in exploring the neighbourhood of any given pair of titles. Previously it was only looking for extensions between two adjacent titles in the chain but now it searches for extensions between end-points in a whole sequence of titles instead. Consider the chain [A,B,C,D,...]. Now, if there's an extension between A and C, other than, and that is longer than [B], the chain is extended with it.

This, simple, tweak makes the search slower (of course) but it also improves the lengths of almost all chains that are explored. It rarely ends up with a chain that is shorter than 235 titles and most end up longer than 250 (246 was the previous best) titles.

The longest chain found is now 265 titles:

1 THE GOSPEL
2 THE GOSPEL OF JOHN
3 JOHN Q
4 Q AND A
5 A RIVER RUNS THROUGH IT
6 IT HAPPENED AT THE WORLDS FAIR
7 FAIR GAME
8 GAME OF DEATH
9 DEATH BECOMES HER
10 HER MAJESTY MRS BROWN
11 BROWN SUGAR
12 SUGAR AND SPICE
13 SPICE WORLD
14 WORLD TRADE CENTER
15 CENTER STAGE
16 STAGE FRIGHT
17 FRIGHT NIGHT
18 NIGHT OF THE LIVING DEAD
19 DEAD BANG
20 BANG BANG YOURE DEAD
21 DEAD MAN WALKING
22 WALKING AND TALKING
23 TALKING ABOUT SEX
24 SEX AND THE OTHER MAN
25 MAN OF THE HOUSE
26 HOUSE OF DRACULA
27 DRACULA DEAD AND LOVING IT
28 IT HAPPENED ONE NIGHT
29 ONE NIGHT STAND
30 STAND IN
31 IN GODS HANDS
32 HANDS ON A HARD BODY
33 BODY AND SOUL
34 SOUL FOOD
35 FOOD OF LOVE
36 LOVE IS THE DEVIL
37 THE DEVIL RIDES OUT
38 OUT COLD
39 COLD FEVER
40 FEVER PITCH
41 PITCH BLACK
42 BLACK LIKE ME
43 ME WITHOUT YOU
44 YOU LIGHT UP MY LIFE
45 MY LIFE SO FAR
46 FAR FROM HOME THE ADVENTURES OF YELLOW DOG
47 DOG RUN
48 RUN SILENT RUN DEEP
49 DEEP BLUE
50 DEEP BLUE SEA
51 SEA OF LOVE
52 LOVE WALKED IN
53 IN OLD CALIFORNIA
54 CALIFORNIA SPLIT
55 SPLIT SECOND
56 SECOND BEST
57 BEST MEN
58 MEN WITH GUNS
59 GUNS OF THE MAGNIFICENT SEVEN
60 THE MAGNIFICENT SEVEN
61 SEVEN YEARS IN TIBET
62 TIBET CRY OF THE SNOW LION
63 LION OF THE DESERT
64 DESERT HEARTS
65 HEARTS OF DARKNESS A FILMMAKERS APOCALYPSE
66 APOCALYPSE NOW
67 NOW YOU SEE HIM NOW YOU DONT
68 DONT BOTHER TO KNOCK
69 KNOCK OFF
70 OFF THE BLACK
71 THE BLACK ANGEL
72 ANGEL EYES
73 EYES OF AN ANGEL
74 ANGEL BABY
75 BABY SECRET OF THE LOST LEGEND
76 LEGEND OF THE LOST
77 THE LOST BOYS
78 BOYS LIFE
79 LIFE OR SOMETHING LIKE IT
80 IT TAKES TWO
81 TWO MEN WENT TO WAR
82 WAR OF THE WORLDS
83 THE WORLDS FASTEST INDIAN
84 INDIAN SUMMER
85 SUMMER CATCH
86 CATCH ME IF YOU CAN
87 YOU CAN COUNT ON ME
88 ME MYSELF I
89 I WANT TO LIVE
90 LIVE FOREVER
91 FOREVER YOUNG
92 YOUNG SHERLOCK HOLMES
93 SHERLOCK HOLMES IN WASHINGTON
94 WASHINGTON SQUARE
95 SQUARE DANCE
96 DANCE WITH A STRANGER
97 STRANGER IN THE HOUSE
98 THE HOUSE OF THE DEAD
99 DEAD OF NIGHT
100 NIGHT AND THE CITY
101 THE CITY
102 CITY OF ANGELS
103 ANGELS WITH DIRTY FACES
104 FACES OF DEATH
105 DEATH WISH
106 WISH UPON A STAR
107 A STAR IS BORN
108 BORN TO BE WILD
109 WILD THINGS
110 THINGS TO COME
111 COME AND GET IT
112 IT RUNS IN THE FAMILY
113 THE FAMILY MAN
114 MAN ON FIRE
115 FIRE ON THE MOUNTAIN
116 THE MOUNTAIN MEN
117 MEN IN BLACK
118 BLACK HAWK DOWN
119 DOWN WITH LOVE
120 LOVE AND DEATH
121 DEATH WISH V THE FACE OF DEATH
122 DEATH SHIP
123 SHIP OF FOOLS
124 FOOLS RUSH IN
125 IN THE WINTER DARK
126 DARK STAR
127 STAR TREK IV THE VOYAGE HOME
128 HOME ALONE
129 ALONE IN THE DARK
130 DARK BLUE
131 BLUE CAR
132 CAR 54 WHERE ARE YOU
133 YOU CANT TAKE IT WITH YOU
134 YOU ONLY LIVE ONCE
135 ONCE IN THE LIFE
136 LIFE AS A HOUSE
137 HOUSE PARTY
138 HOUSE PARTY 3
139 3 NINJAS
140 3 NINJAS KNUCKLE UP
141 UP CLOSE AND PERSONAL
142 PERSONAL BEST
143 BEST OF THE BEST
144 BEST OF THE BEST 3 NO TURNING BACK
145 NO TURNING BACK
146 BACK TO SCHOOL
147 SCHOOL OF ROCK
148 ROCK STAR
149 STAR TREK THE MOTION PICTURE
150 PICTURE BRIDE
151 BRIDE OF THE MONSTER
152 MONSTER HOUSE
153 HOUSE OF FRANKENSTEIN
154 FRANKENSTEIN AND THE MONSTER FROM HELL
155 FROM HELL
156 HELL UP IN HARLEM
157 HARLEM RIVER DRIVE
158 DRIVE ME CRAZY
159 CRAZY AS HELL
160 HELL NIGHT
161 NIGHT FALLS ON MANHATTAN
162 MANHATTAN MURDER MYSTERY
163 MYSTERY ALASKA
164 ALASKA SPIRIT OF THE WILD
165 THE WILD
166 THE WILD ONE
167 ONE NIGHT WITH THE KING
168 THE KING AND I
169 I SPY
170 SPY HARD
171 HARD EIGHT
172 EIGHT MEN OUT
173 OUT OF THE BLUE
174 BLUE SKY
175 SKY HIGH
176 HIGH CRIMES
177 CRIMES OF PASSION
178 PASSION IN THE DESERT
179 DESERT BLUE
180 BLUE STEEL
181 STEEL DAWN
182 DAWN OF THE DEAD
183 THE DEAD
184 DEAD MAN ON CAMPUS
185 CAMPUS MAN
186 MAN TROUBLE
187 TROUBLE EVERY DAY
188 DAY OF THE WOMAN
189 THE WOMAN IN RED
190 RED EYE
191 EYE FOR AN EYE
192 EYE OF GOD
193 GOD TOLD ME TO
194 TO DIE FOR
195 FOR THE BOYS
196 THE BOYS
197 BOYS AND GIRLS
198 GIRLS WILL BE GIRLS
199 GIRLS GIRLS GIRLS
200 GIRLS OF SUMMER
201 SUMMER LOVERS
202 LOVERS AND OTHER STRANGERS
203 STRANGERS WHEN WE MEET
204 MEET JOE BLACK
205 BLACK AND WHITE
206 WHITE HUNTER BLACK HEART
207 HEART CONDITION
208 CONDITION RED
209 RED RIVER
210 RIVER OF NO RETURN
211 RETURN OF THE FLY
212 FLY AWAY HOME
213 HOME ALONE 2 LOST IN NEW YORK
214 NEW YORK NEW YORK
215 NEW YORK COP
216 COP LAND
217 LAND OF THE DEAD
218 DEAD END
219 END OF DAYS
220 DAYS OF HEAVEN
221 HEAVEN CAN WAIT
222 WAIT UNTIL DARK
223 DARK CITY
224 CITY OF JOY
225 JOY RIDE
226 RIDE THE HIGH COUNTRY
227 COUNTRY LIFE
228 LIFE WITH FATHER
229 FATHER OF THE BRIDE
230 BRIDE OF THE WIND
231 THE WIND AND THE LION
232 THE LION KING
233 KING OF THE JUNGLE
234 THE JUNGLE BOOK
235 JUNGLE BOOK
236 BOOK OF LOVE
237 LOVE LIFE
238 LIFE IS BEAUTIFUL
239 BEAUTIFUL PEOPLE
240 PEOPLE I KNOW
241 I KNOW WHERE IM GOING
242 IM GOING HOME
243 HOME ALONE 3
244 3 NINJAS KICK BACK
245 BACK TO THE BEACH
246 BEACH PARTY
247 PARTY MONSTER
248 MONSTER IN A BOX
249 BOX OF MOON LIGHT
250 LIGHT OF DAY
251 DAY FOR NIGHT
252 NIGHT MOTHER
253 MOTHER NIGHT
254 NIGHT ON EARTH
255 EARTH GIRLS ARE EASY
256 EASY MONEY
257 MONEY FOR NOTHING
258 NOTHING BUT TROUBLE
259 TROUBLE IN PARADISE
260 PARADISE ROAD
261 ROAD HOUSE
262 HOUSE PARTY 2
263 2 DAYS IN THE VALLEY
264 VALLEY GIRL
265 GIRL WITH A PEARL EARRING

The results vary a bit depending on search depth (not that surprising really) so there may still be some possible improvements by just modifying parameters.

[Update 2008-07-20] The longest chain found is now 268 titles long.