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Code Issues Releases Wiki Activity

Day 3, part 2

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Chris Josten 2020-12-04 10:32:34 +01:00
parent 52629702c8
commit 2072fc3ed8
Signed by: chris
GPG key ID: 1795A594046530AB
2 changed files with 379 additions and 14 deletions
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source/day3.d
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@ -1,31 +1,73 @@
import std.algorithm;
import std.array;
import std.format;
import std.range;
import std.stdio;
import std.traits;
import std.uni;
import dayutil;
void run(string[] args) {
ulong count = stdin.byLine.countTrees;
auto input = stdin.byLineCopy.array;
ulong count = parts!ulong(args,
() => input.countTrees1,
() => [[1,1], [3,1], [5,1], [7,1], [1,2]]
.map!(x => input.save.enumerate.countTrees2(x[0], x[1]))
.fold!((x, y) => x * y));
writeln(count);
}
ulong countTrees(Range)(Range lines) if (isInputRange!Range) {
ulong countTrees1(Range)(Range lines) if (isInputRange!Range && isSomeString!(ElementType!Range)) {
return lines.enumerate.filter!(x => (x.value[x.index * 3 % x.value.length] == '#')).count;
}
unittest {
string[] field = [
"..##.........##.........##.........##.........##.........##.......",
"#...#...#..#...#...#..#...#...#..#...#...#..#...#...#..#...#...#..",
".#....#..#..#....#..#..#....#..#..#....#..#..#....#..#..#....#..#.",
"..#.#...#.#..#.#...#.#..#.#...#.#..#.#...#.#..#.#...#.#..#.#...#.#",
".#...##..#..#...##..#..#...##..#..#...##..#..#...##..#..#...##..#.",
"..#.##.......#.##.......#.##.......#.##.......#.##.......#.##.....",
".#.#.#....#.#.#.#....#.#.#.#....#.#.#.#....#.#.#.#....#.#.#.#....#",
".#........#.#........#.#........#.#........#.#........#.#........#",
"#.##...#...#.##...#...#.##...#...#.##...#...#.##...#...#.##...#...",
"#...##....##...##....##...##....##...##....##...##....##...##....#",
".#..#...#.#.#..#...#.#.#..#...#.#.#..#...#.#.#..#...#.#.#..#...#.#"
"..##.......",
"#...#...#..",
".#....#..#.",
"..#.#...#.#",
".#...##..#.",
"..#.##.....",
".#.#.#....#",
".#........#",
"#.##...#...",
"#...##....#",
".#..#...#.#"
];
assert(field.countTrees == 7);
assert(field.countTrees1 == 7);
}
// Screw proper template type checking, ain't got time for that.
ulong countTrees2(Range)(Range lines, int advanceX, int advanceY) if (isInputRange!Range)
in (advanceX > 0)
in (advanceY > 0)
out (r; r >= 0) {
return lines.enumerate.filter!(x => {
char c = x.value.value[(x.value.index * advanceX) / advanceY % x.value.value.length];
return (x.index % advanceY) == 0 && c == '#';
}()).count;
}
unittest {
string[] field = [
"..##.......",
"#...#...#..",
".#....#..#.",
"..#.#...#.#",
".#...##..#.",
"..#.##.....",
".#.#.#....#",
".#........#",
"#.##...#...",
"#...##....#",
".#..#...#.#"
];
assert(field.enumerate.countTrees2(1, 1) == 2);
assert(field.enumerate.countTrees2(3, 1) == 7);
assert(field.enumerate.countTrees2(5, 1) == 3);
assert(field.enumerate.countTrees2(7, 1) == 4);
assert(field.enumerate.countTrees2(1, 2) == 2, "Expected 2, got %d".format(field.enumerate.countTrees2(1,2)));
}