47 lines
1.3 KiB
Zig
47 lines
1.3 KiB
Zig
const std = @import("std");
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const util = @import("util.zig");
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const Allocator = std.mem.Allocator;
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const ArrayList = std.ArrayList;
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const tokenize = std.mem.tokenize;
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const print = std.debug.print;
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const gpa = util.gpa;
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const data = @embedFile("input");
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pub fn main() !void {
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// Still have no idea how to clean up the ArrayLists
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var it = tokenize(u8, data, "\n");
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var rows_al = ArrayList([]bool).init(gpa);
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while (it.next()) |line| {
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var row = ArrayList(bool).init(gpa);
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for (line) |char| {
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try row.append(char == '#');
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}
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try rows_al.append(row.toOwnedSlice());
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}
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var rows = rows_al.toOwnedSlice();
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var part_1 = count_trees(rows, 3, 1);
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print("Part 1: {}\n", .{part_1});
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var part_2 = count_trees(rows, 1, 1) * part_1 * count_trees(rows, 5, 1) * count_trees(rows, 7, 1) * count_trees(rows, 1, 2);
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print("Part 2: {}\n", .{part_2});
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}
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fn count_trees(slope: [][]bool, delta_x: usize, delta_y: usize) usize {
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var x: usize = 0;
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var y: usize = 0;
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var count: usize = 0;
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while (y < slope.len) {
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var square = slope[y][x];
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if (square) {
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count += 1;
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}
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x = std.math.mod(usize, x + delta_x, slope[y].len) catch 0;
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y += delta_y;
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}
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return count;
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}
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