Java, 955 bytes
Obviously not going to win any awards, being Java and all, but I love this problem and wanted to throw in my own entry.
Features and limits:
- Can support irregular roads (super drunk!) including variable widths, complex lines, etc.
- Expects road to be input as parameters on execution; the ungolfed version also supports reading from stdin, but since input method wasn't specified the golfed version expects smallest!
- Uses some dynamic programming technique I haven't used in, oh, 6 years or so to efficiently solve in O(n*m) time, where n is rows and m is columns.
- Solves from right to left, marking the best direction to take from the current index to the next index.
- "lines" are handled by resolving their column, then addressing them if reachable on the next column over. They resolve by storing direction up or down, with the cost of the eventually reachable non-line.
- Tracks, but doesn't print (in golf'd version) the starting index of the best solution.
Ok, enough jibba jabba. Golfed version:
class C{public static void main(String[]a){int n=a.length,m=0,i=0,j=0,h=0,p=0,q=0,s=0,t=0,b=-1,c=2147483647,x=0,y=0;char[][]r=new char[n][];char u;for(String k:a){j=k.length();m=(j>m)?j:m;}for(String k:a)r[i++]=java.util.Arrays.copyOf(k.toCharArray(),m);int[][][]d=new int[n][m][2];for(j=m-1;j>=0;j--){for(i=0;i<n;i++){u=r[i][j];p=(u=='\0'||u==' '||u=='|'?0:u-'0');if(j==m-1)d[i][j][1]=p;else{if(u=='|')d[i][j][0]=-1;else{for(h=-1;h<2;h++){x=i+h;y=j+1;if(x>=0&&x<n){if(d[x][y][0]==-1){s=x-1;while(s>=0&&r[s][y]=='|')s--;t=x+1;while(t<n&&r[t][y]=='|')t++;if((s>=0&&t<n&&d[s][y][1]<d[t][y][1])||(s>=0&&t>=n)){t=d[s][y][1];s=4;}else{s=6;t=d[t][y][1];}d[x][y][0]=s;d[x][y][1]=t;}q=d[x][y][1]+p;if(d[i][j][0]==0||q<d[i][j][1]){d[i][j][0]=h+2;d[i][j][1]=q;}}}}}if(j==0&&(b<0||d[i][j][1]<c)){b=i;c=d[i][j][1];}}}String o="";i=b;j=0;while(j<m){u=r[i][j];if(u=='\0')j=m;else{o+=u+",";h=d[i][j][0]-2;if(h>1)i+=h-3;else{i+=h;j++;}}}System.out.println(o+"\b:"+c);}}
As per my habit, github with the ungolfed code.
Solution for "first" road:
$ java C "1356 | 1738" "3822 | 1424" "3527 3718" "9809 | 5926" "0261 | 1947" "7188 4717" "6624 | 9836" "4055 | 9164" "2636 4927" "5926 | 1964" "3144 | 8254"
0,2,0,1, , , ,1,4,1,4:13
Second example:
$ java C "9191 | 8282" "1919 | 2727" "5555 5555"
1,1,1,1, ,|,|, , ,2,2,2,2:12
Brian Tuck's sample:
$ java C "6417443208|153287613" "8540978161|726772300" "7294922506 263609552" "0341937695 498453099" "9417989188 370992778" "2952186385|750207767" "7049868670 756968872" "1961508589|379453595" "0670474005 070712970" "4817414691|670379248" "0297779413|980515509" "6637598208 090265179" "6872950638 767270459" "7375626432 439957105" "1387683792|544956696" "6974831376 545603884" "0949220671|632555651" "3952970630|379291361" "0456363431|275612955" "2973230054|830527885" "5328382365|989887310" "4034587060 614168216" "4487052014|969272974" "5015479667 744253705" "5756698090|621187161" "9444814561|169429694" "7697999461|477558331" "3822442188 206942845" "2787118311|141642208" "2669534759 308252645" "6121516963|554616321" "5509428225|681372307" "6619817314|310054531" "1759758306 453053985" "9356970729|868811209" "4208830142 806643228" "0898841529|102183632" "9692682718|103744380" "5839709581|790845206" "7264919369|982096148"
2,1,0,1,5,1,2,1,1,1, ,1,0,1,2,1,2,3,0,1:26
"Drunkified" Brian's example:
6417443208|153287613
8540978161|726772300
7294922506 263609552
0341937695 498453099
9417989188 370992778
2952186385|750207767
7049868670 756968872
1961508589|379453595
0670474005 070712970
4817414691|670379248
0297779413|980515509
6637598208 090265179
6872950638 767270459
7375626432 439957105
1387683792|544956
697483176 5456034
09492201|6325551
395297030|3792913
456363431|275612
73230054|830527885
8382365|989887310
4587060 614168216
87052014|96927297
50479667 7442537
57566980 | 621187161
944481456 | 169429694
7697999461|477558331
3822442188 206942845
2787118311|141642208
2669534759 308252645
6121516963|554616321
5509428225|681372307
6619817314|310054531
1759758306 453053985
9356970729|868811209
4208830142 806643228
0898841529|102183632
9692682718|103744380
5839709581|790845206
7264919369|982096148
$ java C "6417443208|153287613" "8540978161|726772300" "7294922506 263609552" "0341937695 498453099" "9417989188 370992778" "2952186385|750207767" "7049868670 756968872" "1961508589|379453595" "0670474005 070712970" "4817414691|670379248" "0297779413|980515509" "6637598208 090265179" "6872950638 767270459" "7375626432 439957105" "1387683792|544956" "697483176 5456034" "09492201|6325551" "395297030|3792913" " 456363431|275612" " 73230054|830527885" " 8382365|989887310" " 4587060 614168216" " 87052014|96927297" " 50479667 7442537" "57566980 | 621187161" "944481456 | 169429694" "7697999461|477558331" "3822442188 206942845" "2787118311|141642208" "2669534759 308252645" "6121516963|554616321" "5509428225|681372307" "6619817314|310054531" "1759758306 453053985" "9356970729|868811209" "4208830142 806643228" "0898841529|102183632" "9692682718|103744380" "5839709581|790845206" "7264919369|982096148"
, , , ,0,5,2,0,1, , , ,1,1,1,3,2:16
Solution visualized:
09492201|6325551
395297030|3792913
\456363431|275612
\73230054|830527885
\ 8382365|989887310
\4\87060 614168216
87/5--\4|96927\97
50479667\74425/7
57566980 |\62-/87161
944481456 |\/69429694
7697999461|477558331
Enjoy!
Edit: Now I'm just showing off (two roadways merge! Can he make it?)
948384 | 4288324 324324 | 121323
120390 | 1232133 598732 | 123844
293009 | 2394023 432099 | 230943
234882 | 2340909 843893 | 849728
238984 | 328498984328 | 230949
509093 | 904389823787 | 439898
438989 | 3489889344 | 438984
989789 | 7568945968 | 989455
568956 | 56985869 | 568956
988596 | 98569887 | 769865
769879 | 769078 | 678977
679856 | 568967 | 658957
988798 | 8776 | 987979
987878 | 9899 | 989899
999889 | | 989899
989999 | | 989999
989898 | | 998999
989999 | | 999999
989998 || 899999
989998 || 998999
Solution:
$ java C "948384 | 4288324 324324 | 121323" "120390 | 1232133 598732 | 123844" " 293009 | 2394023 432099 | 230943" " 234882 | 2340909 843893 | 849728" " 238984 | 328498984328 | 230949" " 509093 | 904389823787 | 439898" " 438989 | 3489889344 | 438984" " 989789 | 7568945968 | 989455" " 568956 | 56985869 | 568956" " 988596 | 98569887 | 769865" " 769879 | 769078 | 678977" " 679856 | 568967 | 658957" " 988798 | 8776 | 987979" " 987878 | 9899 | 989899" " 999889 | | 989899" " 989999 | | 989999" " 989898 | | 998999" " 989999 | | 999999" " 989998 || 899999" " 989998 || 998999"
,2,0,3,0,0, ,|,|, ,|,|, ,|,|, ,|,|, ,|,|, ,|,|, ,|,|, , , , , , , ,|, ,|, ,|, ,|, ,|, ,|, ,|,|, , ,1,0,7,2:15
(bonus: path from ungolfed):
$ java Chicken < test5.txt
best start: 3 cost: 15
-> 2 -> 0 -> 3 -> 0 -> 0 -> -> | -> | -> -> | -> | -> -> | -> | -> -> | -> | -> -> | -> | -> -> | -> | ->
-> | -> | -> -> -> -> -> -> -> -> | -> -> | -> -> | -> -> | -> -> | -> -> | -> -> | -> | ->
-> -> 1 -> 0 -> 7 -> 2 -> 15
/ -> - -> - -> \ -> / -> / -> - -> , -> , -> - -> , -> , -> - -> , -> , -> - -> , -> , -> - -> , -> , -> - -> , -> , ->
- -> , -> , -> / -> \ -> - -> - -> - -> / -> / -> ^ -> / -> ^ -> / -> ^ -> / -> ^ -> / -> ^ -> / -> ^ -> / -> , -> , ->
/ -> - -> \ -> \ -> - -> \ -> across
Details on Algorithm
A more complete explanation of the Dynamic Programming technique I employed was requested, so here goes:
I'm using a mark-and-precompute method of solution. It has a proper name, but I've long since forgotten it; perhaps someone else can offer it?
Algorithm:
- Starting at the right-most column and progressing to the left, compute the following about each cell in the column:
- The summation of lowest cost movement, defined as current cell cost + lowest cost cell reachable in the next column
- The movement action to take to achieve this lowest cost, as simply a valid move from this cell to another single cell.
- Pipes are deferred. To resolve a pipe, you need to have the full column computed, so we don't compute pipes until the next column.
- When determining the lowest cost of a cell to the left of a pipe, we first compute the best direction to travel along the pipe -- it will always resolve to either up, or down, so we compute it once.
- We then store, as with all other cells, the best cost (defined as the cost of the cell we reach by travelling either up or down on the pipe) and the direction to travel to reach it.
Notes:
That's it. We scan from top to bottom, right to left, once; the only cells touched (potentially) more then once are pipes, however, each pipe is only "solved" once, keeping us within our O(m*n) window.
To handle "odd" map sizes, I chose to simply pre-scan and normalize lengths of rows by padding with null characters. Null characters count as "zero cost" moves same as pipes and spaces. Then, in printing the solution, I stop printing costs or moves when either the edge of the normalized road is reached, or a null character is reached.
The beauty of this algorithm is it's very simple, applies the same rules to every cell, producing a full solution by solving O(m*n) sub-problems, and in terms of speed is rather fast. It does trade off memory, creating effectively two copies in memory of the roadway map, the first to store "best cost" data and the second to store "best move" data per cell; this is typical for dynamic programming.
|in a row? \$\endgroup\$0,2,0,1, , , ,1,4,1,4 -> 13\$\endgroup\$