Imagine Cup 2008 Match 1 Summary

LeaderBoard

 

1	Rac	47687	Poland	Politechnika Krakowska
2	Jedi_Knight	47326	Russia	Moscow State University
3	XarN	46798	Poland	AGH University of Science and Technology
4	chokudai	46085	Japan	Senior High School at Komaba, University of Tsukuba
5	Eirik Reksten	44674	Norway	Norwegian University of Science and Technology
6	szsz	44297	Hungary	Illyes Gyula High School
7	FloppyCat	43826	Lithuania	vilnius university
8	sempik	43620	Poland	Jagiellonian University
9	JasonKing	43603	China	HUST
10	r1cs1	43511	Hungary	Budapest University of Technology and Economics
11	kim-my	43446	Russia	MSU
12	Xianchao	43271	United States	Harvard University
13	Gribok	43221	Russia	Ivanovo State Power University
14	jackvsalmond	43038	China	Huazhong University of Science and Techmnology
15	Lyt	42966	China	Huazhong University of Science and Technology
16	kg86	42931	Poland	Jagiellonian University
17	DjubaRS	42545	Russia	Moscow Institute of Physics and Technologies (MIPT)
18	EmK	42507	Japan	Saitama University
19	ardiankp	42415	Indonesia	NANYANG TECHNOLOGICAL UNIVERSITY
20	Gorion	42386	Poland	Warsaw University
21	Jamal	42385	Poland	Wroclaw University of Technology, Faculty of Informatics and Management
22	Krochak	42367	Russia	Moscow state Aviation Institute
23	permil	42365	Japan	Tokyo Institute of Technology
24	mrLEE	42359	Russia	Moscow state Aviation Institute
25	Slimi	42344	Morocco	EMSI
26	Castle.Derek	41978	China	华工
27	shaoanxu	41934	China	tsinghua university
28	Mr.Herbert	41885	China	华中科技大学
29	TOP	41877	China	tsinghua university
30	Leszek Horwath	41868	Poland	Jagiellonian University
31	Skadanov Alex	41740	Russia	Izhevsk State Technical University
32	viewlagoon	41731	Japan	筑波大学附属駒場高等学校
33	Grey	41610	Russia	Ivanovo State University of Chemistry and Technology
34	Lanethan	41555	Singapore	Carnegie Mellon University
35	minhduc	41516	Viet Nam	National University of Singapore
36	spring.field	41515	China	华科大
37	KTropin	41393	Russia	Moscow Institute of Physics and Technologies (MIPT)
38	lunar	41277	Japan	Takada High School
39	mostafaizz	41223	Egypt	Cairo University - Faculty of Engineering
40	Herbi	41060	Poland	Wroclaw University of Technology, Faculty of Informatics and Management
41	Roman Koshlyak	41043	Ukraine	Kiev National University
42	Diab1o	41008	Russia	Moscow state Aviation Institute
43	monae	40866	Japan	University of Tokyo
44	Piovesan Carlo	40865	Italy	Scuola Superiore Sant'Anna
45	Vanka	40583	Russia	SPb SPU
46	andrejko	40477	Serbia	Faculty of Mathematics and Sciences Nis
47	Exelle	40105	Romania	"Al. I. Cuza" University of Iasi
48	yunfzhang	39837	China	Hohai Unversity
49	MevanAlles	39751	Sri Lanka	Department of Computer Science & Engineering ( CSE ), University of Moratuwa
50	snard6	39681	United States	University of Utah

87

duguguiyu

31772

China

tsinghua university

 

Level Stats

 

Levelx	Num Solvesx	Avg Time To Solve (HH:MM:SS)x	Min Bytesx	Avg Bytes of Solutionsx	Max Pointsx	# Max Point Solutions
1	1240	0:01:58	9	16.3	244	24
2	780	0:04:36	11	13.5	381	9
3	1047	0:01:35	12	16.9	733	99
4	384	0:09:45	18	20.8	466	1
5	783	0:02:17	22	28.5	704	1
6	481	0:06:07	13	18.7	769	13
7	392	0:06:00	20	23.0	1300	26
8	159	0:13:05	23	24.2	1291	75
9	145	0:15:14	25	28.8	1364	5
10	424	0:06:08	19	25.9	1831	1
11	361	0:06:20	18	27.6	2133	1
12	474	0:03:12	15	19.3	1820	75
13	90	0:22:33	35	40.1	1597	7
14	123	0:16:46	22	24.7	1718	3
15	566	0:04:11	21	30.1	2428	8
16	669	0:02:04	12	25.2	4750	12
17	2	0:49:40	26	26.0	1500	2
18	10	1:01:45	21	21.0	1600	10
19	426	0:03:26	16	21.6	2443	21
20	119	0:22:26	10	13.8	3570	13
21	167	0:21:53	13	19.2	3046	17
22	113	0:19:26	15	17.0	2640	43
23	368	0:05:52	13	21.8	4500	65
24	287	0:07:48	26	31.3	3096	3
25	373	0:12:28	15	32.4	7200	1

 

Experiences about random paths

 

I don't say whether random paths are nice or not, but in match 1 random paths definitely give not less than 5k.
The high-points levels in which random paths applied are 16 (+3k!), 20, 25 (+4k!)

There are some points here:

- In levels which have few grey dots, there are 99% about existence of random paths (as in level 16, 20)

- Even in levels which have a half of grey dots and wall like level 25, there are still random paths.

Level 25: This is because grey dots only appears in the even rows/even columns and in the sides of map. So if we consider for example ssllssss is a pace, there appears a bunch of random paths!

So,

- What kind of map can avoid random paths?

The answer: "map that have many grey dots"  are definitely not true.

I hope everyone will share your opinions / experiences. 

 

After using some random paths, I wanna to share my little knowledge for Herbert's newbies in later match (in case there are still such beneficial levels :) )

A random path is actually not random (each time, it behaves similarly). Because of the complex characteristics of wall\side effect, however, a random path behaves unpredictably.

I have seen two groups of random paths:

* With numbers:
e.g.
f(N):sf(N-5)rf(N-7)
f(41)

* Without numbers:
e.g.
f(A):Af(ArAA)
f(s)

In fact, random paths behave very randomly. In level 16, my random path does not guarantee to not touch the grey dots, and it did touch the grey dots for some times. However, it still solved the level, and the only reason I have for this case is there are so few grey dots. In level 25, I even found a path that touched every white dots except one. (I guess it's even harder to find this than to find a solution :p)

But in certain cases, I believe there are some rules. A simple rule is that you realize there is a unit step, say x, such that if you call x (assigned to A) then call a simple combination of A, r, l, e.g. ArAA, then call that combination again, etc... you will surely not touch the grey dots. Your path will only run in a certain region of the map. Try and see:
f(A):Af(AAlA)
f(ss)

In many cases, it seems that your path's region covers all the white dots, but why doesn't it touch all? I don't understand this (and also don't know whether it can be understandable) :p. So here a computer program will have you find the solution faster. Remember, if you find a random path that earns about 1/3 points (e.g. 1000/3000), you can believe that there is a random solution.

Random paths are often very short and can help earn a lot points. But some are very slow, for example my solution on level 25 took me 3 hours to run on ICHerbert.

From my experience, I have this form of random path:
f(A):Af( [a combination of x, l, r, A] )
f()
Where x is the unit step.

I hope people, especially the experts like Rac, Sempik... will share your knowledge.

Finally, there are some talented ones who did not use random path but still stayed at top places (Chokudai is one of them). However, I believe that when this game becomes more popular, there will be more people using simulators. Then if there are still such levels, someday you won't be qualified without random paths. I hope I'm not right :)

 

Problems

 

6

7

8

9

10

11

12

13

14

17

18

19

20

21

22

23

24

25

 

Solutions

 

Top 1 : Rac

1: simu  (9)

4:
f(X):lXXX
rf(f(ssf(ss)sslf(s)s))     I dont remember if I had not 19 bytes solution...

5:
f(X,Y):YYYYf(sXsrsl,ssXrrXssl)   (24)
f(,)

6:
f(X,Y):rXf(ssXY,Ys)          (17)
f(srs,s)

7:
f(X,Y):rXf(X,Y-1)            (20)
f(f(f(slsss,12),2),20)

8:
f(X):df(X-1)                (24)
d:lsrs
m:f(9)rsf(10)sldlm
m

9:
f(X):XXrs                (25)
c:ssss
d:f(f(clf(c)lcr)sr)d
d

10:
f(X):srslf(X-1)              (23)
c:f(12)lf(11)lf(13)lssc
c

11:
g(X,Y):XXXXYX               (20)
g(g(g(g(g(s,r)l,)rr,)r,),)

12:
f(X):XXrf(Xssrssl)          (15)
f(r)

13:
c:m(m(s,),)                         (39)
m(X,Y):XYX
g(X,Y):g(srslX,Y-1)m(cXXsc,m(XlX,)s)csrr
g(r,4)

14:
f(X,Y):Xssrsssrf(sX,Y-1)    
f(ls,14)f(ssl,100)

in fact had 24 solution, very similar to this one
something close to
f(X,Y):Xsslssrsssrf(sX,Y-1)
lf(,15)f(,100)

15:
f(Y):srslf(Y-1)r                     (22)
c:f(12)rssf(11)f(26)c
c

16:
f(X,Y):rXf(Xssss,Y-1)f(,15)          (17)
f(,14)

f(X):Xf(XrXsl)                  (SIMU)   (12)
f(ss)

17:
g(X,Y):XXsXddXsg(Xd,Y-1)        (partial 30 - pattern,   28 - for  more points)
d:ss
c:rrdg(ls,7)c
sc

g(X,Y):XXsXddXsg(Xd,Y-1)l
d:ss
srg(rdg(ls,7),1)

18:     (21/21) (favourite level of most competitiors :P)
f(X):srslf(X-1)ssl
c:f(18)f(15)f(2)c
c

19:     (16)
f(X):lssrssf(X-1)rf(9)
f(9)

20:     (SIMU)   (10)
f(X):Xf(lXrXs)
f()

21:      (14)
f(X):XXf(Xllsrsr)
f(l)

22:      (15)
it was something like:
f(X,Y):Xf(YlXXlY,Yss)
f(,)

23:  (13 or 14)  (SIMU)

24:
f(X,Y):drXldlXrf(Xdd,Y-1)       (30)
d:ss
c:f(d,3)f(d,3)rc
c

25:                             (25)
f(X,Y):f(ssX,Y-1)XssrXr
c:f(r,13)f(l,3)lc
c

To solve 18 most important thing was to realize that this strange squares can be drawn by sometihng like
f(X):something f(X-1)ssl
Drawing square in the end of path additionally turns the robot in a direction depending on length of path.
I assumed that only possible solution (if using described function and taking into consideration symmetry)
must be
f(X):Af(X-1)B
c:f(C)f(D)f(E)c
c
where A belongs to {slsr,lsrs,srsl,rsls}     B belongs to {ssl,ssr,lss,rss,srs,lsl}
where C,D,E were such numbers that robot would end path drawing a square (squares were easy to recognize)
Now we have to eliminate possibilities, or use simu to do that faster ;)
It was one of most difficult levels, and in fact it was accident that i managed to solve it.

Top 4 : chokudai

 

My solutions is here.
http://chota.mine.nu/herbert/2008_1.txt

Min bytes Solutions

1,9/22(min:9)
a(A):Aa(sAAr)
a()

3,12/22(min:12)
a(A):Alsssla(As)
a()

7,20/26(min:20)
b(B,C):CCCCb(slsssrB,BBr)
b(r,)

8,23/27(min:23)
a(A):lsrsa(A-1)
f:a(9)rsa(10)sla(1)lf
f

9,25/31(min:25)
a(A):AAr
d:ssss
f:a(a(dla(d)sldr)a(s))f
f

12,15/21(min:15)
b(B):BBrb(Bssrssl)
b(r)

14,22/27(min:22)
a(A):b()Alb()sa(As)
b(B):sBsBr
b(b(ss))a()

18,21/21(min:21)
a(A):srsla(A-1)ssl
b:a(22)a(15)a(2)b
b

19,16/23(min:16)
d(D):ssrssld(D-1)rd(9)
d(9)

20,10/21(min:10) (using simulator :(
a(A):Aa(lArAs)
a()

22,15/22(min:15)
b(B,C):Bb(CrBBrC,Css)
b(,)

23,13/26(min:13)
b(B):Brrb(ssrslB)
b()

24,26/35(min:26)
a(A,B,C):BBAa(Ass,rrB,C-1)
a(a(r,a(,rss,6),1),,10)

Now I find shortest Level 13

Level 13 35/43(min:35)
a(A):ssssAAs
c(D,E):c(srslD,E-1)a(D)a(DlD)a(D)a()sa(r)
c(r,4)

 

Top 5 : Eirik Reksten

 

Level 21 (13/22):
b(A):AAb(srslA)
b(ls)

 

Level 23 (13/26):
e(A):Arre(ssrslA)
e()

 

Top 6 : szsz

 

1 9/14

q(X):Xq(sXXl)

q()

 

2 11/14

q(X):Xq(XssXrX)

q()

 

3 15/22

d:sslsssl

a:ddssa

a

 

4 21/21

q:ss

w:qlqqqqrrqq

h:lwww

hh

 

5 25/31

a(X):XXXXX

g:a(s)a(srsl)

a(ssgrrgssr)

 

6 17/20

a(X):XXXX

p:srsl

a(ssa(a(s)sa(p)prr)rrssr)

 

7 22/26

a(X):XXX

f:rsla(s)

q:a(a(f))l

a(a(qqfl))

 

8 -/27

 

9 31/31

a(X):XX

d:a(ss)

w:a(rdlddrsld)

lwa(a(a(rrsswlw)))

 

10 23/29

a(X):slsra(X-1)

q:a(11)sla(10)sla(12)lq

q

 

11 25/32

a(X):XXXXX

b(X):a(X)b(rslsssa(sr)lX)

b(r)

 

12 15/21

g(X):XlXg(lXsslssr)

g()

 

13 -/43

 

14 23/27

q(X,Y):lssrsssrXq(Xs,Y-1)

q(,21)rrq(,25)

 

15 24/34

f(X):slsrf(X-1)

w:f(11)l

d(X):ssXd(Xwlw)

d()

 

16 12/38

q(X):Xq(slXssX)

q(r)

 

17 -/26

 

18 -21

 

19 20/23

a(X):XXX

g:ra(a(rsslss))

a(a(grg))

d

 

20 10/21

q(X):Xq(lXXs)

q(l)

 

21 18/22

q:slsr

d(X):XXXXd(Xqqq)

d(r)

 

22 17/22

h(X,Y):XXh(YXXrYl,Yss)

h(,r)

 

23 13/26

d(X):Xd(ssrslX)

d(rr)

 

24 30/35

w:ss

d(X,Y):rwrXlwlXd(Xww,Y-1)

g:d(w,3)

c:rggc

c

 

25 15/36

q(X):XXq(rssXXr)

q(sss)

Top 7 : FloppyCat

level 17

a(X,Y,N):XYa(Yss,X,N-1)
q:lla(sls,lss,14)q
q

a(X,Y,N):XYa(Yss,X,N-1)lla(sls,lss,14)
a(,,1)

 

Top 8 : sempik

 

Lvl 6: 14/20 bytes
f(X,Y):XYf(sXs,Xl)
f(sl,)

Lvl 9: 27/31
w:ssss
b:wlwwrslwr
c:bbrssrbblc
c

Lvl 10: 23/29
w(A):rslsw(A-1)
a:w(12)lsw(10)lsw(11)la
a

Lvl 13: 37/43
v:sssss
g(A,X):sg(A-1,srslX)XXvXlXXlXvXXvsrr
g(4,r)

Lvl 15: 24/34
w(A):srslw(A-1)
v:w(12)rssw(11)
vlw(23)llv

Lvl 16: 12/38
f(X):Xf(slXsX)
f(rs)

Lvl 19: 17/23
t(X):XXX
t(t(t(rt(t(sslssr)))))

Lvl 20: 10/21
f(X):Xf(lXrXs)
f()

Lvl 21: 13/22
f(X):XXf(Xlsrs)
lf(l)

Lvl 23: 13/26
f(X):Xf(ssrslX)
f(ll)

 

Top 21 : Jamal

 

level which I had better done than sempik or Rac only :

6 13 20
f(A,B):Af(lBABr,Bs)
f(,)

 

15 21 34
x(A):sx(A-1)
f(A):x(A)lx(24)lf(A-2)
f(23)f(25)

 

19 16 23
x(A):sslssrx(A-1)rx(9)
x(9)

 

======================

all of my solutions, for someone who is interested in: 

1 12 22
f(A):AAf(Aslsr)
f(r)
 
2 13 14
z:ssrsss
f:lzzf
f

3 12 22
x(A):Alssslx(sA)
x()

4 21 21
x:ssss
z:sslxxllx
f:lzzzf
f

5 24 31
x(A):rslsx(A-1)s
f:x(5)ssl
z:ssflfz
z

6 13 20
f(A,B):Af(lBABr,Bs)
f(,)

7 21 26
x(A):rslsssx(A-1)
f:x(12)r
g:ffrg
g

8 23 27
x(A):lsrsx(A-1)
z:x(9)rsx(10)slx(1)lz
z

9 27 31
x:ssss
w:xlxxrslxr
f:wrssrwwlf
wf
 
10 23 29
x(A):rslsx(A-1)
g:x(12)lsx(10)lsx(11)lg
g

11 23 32
u(A):AAA
h:u(ru(s)srs)ll
u(u(u(h)srhh))

12 15 21
x(A):AArx(sslssrA)
x(r)

13 42 43
z:ssss
f:lsrs
h(A):rArAzs
g(A,B,C):g(ffA,fB,C-1)h(B)h(A)h(B)sll
zg(,,4)

14 24 27
z(A):Alssrxrz(As)
x:sss
xxxxrxz(s)

15 21 34
x(A):sx(A-1)
f(A):x(A)lx(24)lf(A-2)
f(23)f(25)

16 19 38
w(A):AAAA
w(lw(lw(rw(w(s))))llw(s))

17 ----
 
18 21 21 (not full solution)
x(A):srslx(A-1)
g:x(18)rx(9)rx(8)rg
g

19 16 23
x(A):sslssrx(A-1)rx(9)
x(9)

20 12 21
x(A):sx(A-5)lx(A-7)
x(87)

21 21 22
z:rslsr
x(A,B):zAzBx(sssB,A)
x(s,)

22 15 22
z(A,B):Bz(ssA,ArBBrA)
z(,)

23 13 26
g(B):Bllg(ssrslB)
g()

24 30 35
a:ss
g(A,B):g(A-1,aaB)BrarBlal
z:g(3,a)
h:zlzh
h

25 25 36
f(A,B):sf(Ass,B-1)rArssrAr
g:f(,13)rsg
g

 

Top 35 : minhduc

 

Level 13:
My solution: 41/43 (heart-shaped :)
y:ssss
c(N,A,B):c(N-1,Alsrs,AAysAlAAlAysAAyssll)B
yc(5,r,)

I'd like to see shorter solution...

 

Level 16:
My solution: 16/38 (random)
f(A):Af(AAlAAl)
f(rssss)

I wonder what the min-bytes solution looks like :|

 

Level 22: 17/22 (a fractal pattern)
f(A,B):Blf(ssA,ABrBA)
f(l,r)

 Again, what's about 15/22..

 

Level 25: 16/36 (random)

f(A):Af(lAAllAAssAr)
f()

 

Top 49 : MevanAlles

 

Level 5 - 23 / 31

f(A):srslf(A-1)ss
a:sf(5)lslf(4)la
a

 

Level 10  22 / 29

f(A):srslf(A-1)
b:lsf(12)
a:blf(11)ba
a

 

Level 11 23 / 32 

f(A):AAAA
b:f(f(s)rsl)sssr
f(f(f(b)bs))

 

Level 12  16 / 21

f(A):ArArrf(ssrsslA)
f()

 

Level 13  43 / 43 ( i hate this level even if I solved it :( )

g(A,B):AABAA
b:g(s,s)
f(A,C):f(srslA,C-1)g(s,)rg(A,rbg(Ar,rr)b)
g(b,rr)sf(,4)

 

Level 14 24 / 27

a:ssrsss
f(A):Alarf(sA)
alasrraf()

 

Level 16 20 / 38

a:ssss
f(A):Alf(araAala)
f(rr)

 

Level 17 (partial, feel sad as I cudnt compress this solutions to 26 bytes... :( )

 37 /26

f(A,B):ABA
g(A,B):f(f(Al,s),f(ss,))g(ssA,B-1)
a:g(s,7)lssla
rrsla
 

another one

40 / 26

f(A,B):AlAslAsslAssssslf(ssA,B-1)
b:lsf(,7)lf(,1)f(,1)f(,1)b
lb

 

Level 18 ( this too i found this last night didnt have time to change the approach to get in max bytes :(. I went clockwise & ended up with this.. I wud have figured it out if I went to anti clock wise approach lols. but feels sad though almost had it  )

29 / 21 

f(A):lsrsf(A-1)srs
b:f(4)f(8)rf(9)f(9)f(4)rf(3)b
b

 

Level 19/ 23

f(A):sslssrf(A-1)r
a:f(9)f(10)a
a

 

Level 20  21 / 21

this is the 21 byte solution I found.
g(A):rg(A-3)ssssrssslg(A-5)s
g(151)

This below one is a non random path for Level 20. I would  be thankful if someone can let me know a way of optimizing it. it went 29/21

f(A):srslf(A-1)l
g(A):f(A)rf(A-1)f(A-2)f(A-3)g(A-4)
g(24)

 

Level 22 15 / 22

f(A,B):Af(BlAAlB,ssB)
f(,)

 

Level 23  13 / 26

f(A):Arrf(ssrslA)
f()

 

Level 24  30 / 35
a:ss
f(A,B):arAlalArf(aaA,B-1)
b:f(a,3)
c:bbrc
c

 

Level 25

Best one 26 / 36

g(A,B,C):g(A-2,ssB,Br)rCssrC
b:g(28,,)rg(14,,)b
b

Another path  28 / 36

f(A):sf(A-1)
g(A):f(A)rssrf(A)rrg(A-2)s
d:g(24)ld
d