const std = @import("std");
const Allocator = std.mem.Allocator;

pub fn run(_: Allocator, input: []u8) !struct { u64, u64 } {
    var lines = std.mem.tokenizeScalar(u8, input, '\n');

    var answer1: u64 = 0;
    var answer2: u64 = 0;
    while (lines.next()) |line| {
        answer1 += try calculateJoltage(line, 2);
        answer2 += try calculateJoltage(line, 12);
    }

    return .{ answer1, answer2 };
}

fn calculateJoltage(line: []const u8, num_digits: usize) !u64 {
    var index: usize = 0;
    var value: usize = 0;
    var total: usize = 0;
    for (0..num_digits) |i| {
        const start = if (i == 0) 0 else index + 1;
        const end = line.len - (num_digits - i - 1);

        index = std.mem.indexOfMax(u8, line[start..end]) + start;
        value = try std.fmt.charToDigit(line[index], 10);

        total += value * std.math.pow(usize, 10, num_digits - i - 1);
    }

    return total;
}