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comparison 2017/day19/app.d @ 33:bc652fa0a645

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Move all solutions to per-day subdirs
author Jordi Gutiérrez Hermoso <jordigh@octave.org>
date Tue, 09 Jan 2018 21:50:37 -0500
parents 2017/day19.d@836d284fff87
children
comparison
equal deleted inserted replaced
32:763c88851b91 33:bc652fa0a645
1 import std.stdio;
2 import std.array: array;
3 import std.algorithm: map;
4 import std.string: indexOf;
5 import std.typecons: tuple;
6
7 auto walkPath(T)(T grid) {
8 char[] path;
9 long i = grid[0].indexOf("|"), j = 1;
10 int steps = 1;
11 enum DIR {u, d, l, r};
12 DIR dir = DIR.d;
13 while(i > 0) {
14 steps++;
15 auto next = grid[j][i];
16
17 switch(next) {
18 case 'A': .. case 'Z':
19 path ~= next;
20 break;
21 case '+':
22 if(dir == DIR.u || dir == DIR.d) {
23 if(grid[j][i-1] == '-') {
24 dir = DIR.l;
25 }
26 else {
27 dir = DIR.r;
28 }
29 }
30 else {
31 if(grid[j-1][i] == '|') {
32 dir = DIR.u;
33 }
34 else {
35 dir = DIR.d;
36 }
37 }
38 break;
39 default:
40 }
41
42 final switch(dir){
43 case DIR.d:
44 j++;
45 break;
46 case DIR.u:
47 j--;
48 break;
49 case DIR.l:
50 i--;
51 break;
52 case DIR.r:
53 i++;
54 break;
55 }
56
57 }
58 return tuple(path, steps);
59 }
60
61 void main(string[] args) {
62 auto grid = File(args[1]).byLineCopy.array.dup;
63 auto ret = grid.walkPath;
64 writeln(ret[0]);
65 writeln(ret[1]);
66 }