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const std = @import("std");
pub fn main() !void {
var gpa = std.heap.GeneralPurposeAllocator(.{}){};
defer _ = gpa.deinit();
const alloc = gpa.allocator();
const path = "input.txt";
const fp = try std.fs.cwd().openFile(path, .{.mode = std.fs.File.OpenMode.read_only});
defer fp.close();
var reader = fp.reader();
var buffer: [256]u8 = undefined;
var beams = std.AutoHashMap(usize, u64).init(alloc);
defer beams.deinit();
while(try reader.readUntilDelimiterOrEof(&buffer, '\n')) |line| {
if(beams.count() == 0){
try beams.put(std.mem.indexOf(u8, line, "S").?, 1);
continue;
}
for(line, 0..) |l, i| {
if(l == '^' and beams.contains(i)){
const val = beams.get(i).?;
if(beams.contains(i + 1)) { try beams.put(i + 1, beams.get(i + 1).? + val); }
else try beams.put(i + 1, val);
if(beams.contains(i - 1)) { try beams.put(i - 1, beams.get(i - 1).? + val); }
else try beams.put(i - 1, val);
try beams.put(i, 0);
}
}
}
var k = beams.iterator();
var timelines: u64 = 0;
while(k.next()) |o| {
timelines += o.value_ptr.*;
}
std.debug.print("{d}\n", .{timelines});
}
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