49 lines
1.5 KiB
Rust
49 lines
1.5 KiB
Rust
// Copyright 2022 Christian Ulrich
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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//
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// usage: ./part1 < input
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use std::io;
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fn accumulated_calories() -> Result<Vec<usize>, &'static str> {
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let mut result = vec![];
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let mut acc = None;
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for line in io::stdin().lines() {
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let line = line.unwrap();
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if line.len() == 0 {
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if let Some(value) = acc {
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result.push(value);
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acc = None;
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}
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} else {
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match line.parse::<usize>() {
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Ok(value) => acc = Some(acc.unwrap_or(0) + value),
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Err(_) => return Err("input file contains invalid line"),
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}
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}
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}
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if let Some(value) = acc {
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result.push(value)
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}
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Ok(result)
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}
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fn main() -> Result<(), &'static str> {
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let mut calories = accumulated_calories()?;
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calories.sort();
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println!("{}", calories.last().ok_or("input file is empty")?);
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Ok(())
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}
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