38 lines
1.1 KiB
Zig
38 lines
1.1 KiB
Zig
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const std = @import("std");
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const example = @embedFile("example");
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const input = @embedFile("input");
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pub fn main() anyerror!void {
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try std.testing.expectEqual(solve(example), 13140);
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const result = solve(input);
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try std.io.getStdOut().writer().print("{}\n", .{result});
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}
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fn solve(puzzle: []const u8) i64 {
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var it = std.mem.tokenize(u8, puzzle, "\n");
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var tot: i64 = 0;
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var cycle: i64 = 1;
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var x: i64 = 1;
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var line: []const u8 = undefined;
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var prev: ?i64 = null;
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// process input
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while (cycle <= 220) : (cycle += 1) {
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if (@mod(cycle - 20, 40) == 0) {
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tot += x * cycle;
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}
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if (prev) |p| { // cpu is busy adding
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x += p;
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prev = null;
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} else { // read another instruction
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line = it.next() orelse break;
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if (line[0] == 'a') {
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var elts = std.mem.split(u8, line, " ");
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_ = elts.next() orelse unreachable;
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prev = std.fmt.parseInt(i64, elts.next() orelse unreachable, 10) catch unreachable;
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}
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}
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}
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return tot;
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}
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