40 lines
691 B
D
40 lines
691 B
D
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import std;
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void main()
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{
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File("input", "r").byLineCopy.array.countTrees(3, 1).writeln;
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}
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ulong countTrees(T)(T input, int angleX, int angleY)
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in(input.length > 0)
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{
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immutable width = input[0].length;
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size_t count = 0;
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size_t x = 0;
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return input.stride(angleY).map!((row) {
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auto result = row[x];
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x = (x + angleX) % width;
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return result;
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})
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.filter!(pos => pos == '#')
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.count;
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}
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unittest
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{
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auto input = `..##.......
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#...#...#..
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.#....#..#.
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..#.#...#.#
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.#...##..#.
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..#.##.....
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.#.#.#....#
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.#........#
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#.##...#...
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#...##....#
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.#..#...#.#`.byChar.splitter("\n").map!array.array;
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assert(input.countTrees(3, 1) == 7);
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}
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