Nick Thomas
cb0c5fa868
git-subtree-dir: 2018 git-subtree-mainline:5ccd921b23git-subtree-split:4f35fa8515
46 lines
1.1 KiB
Rust
46 lines
1.1 KiB
Rust
use std::collections::HashSet;
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use std::error::Error;
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use std::fs::File;
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use std::io::BufReader;
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use std::io::SeekFrom;
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use std::io::prelude::*;
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fn main() -> std::io::Result<()> {
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let mut file = match File::open("input") {
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// The `description` method of `io::Error` returns a string that describes the error
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Err(why) => panic!("couldn't open input: {}", Error::description(&why)),
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Ok(file) => file,
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};
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let mut repeat = true;
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let mut total: i128 = 0;
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let mut seen = HashSet::<i128>::new();
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seen.insert(0);
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while repeat {
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file.seek(SeekFrom::Start(0));
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let reader = BufReader::new(&file);
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let lines = reader.lines();
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for result in lines {
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let l = result.unwrap();
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let offset:i128 = i128::from_str_radix(&l, 10).unwrap();
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total = total + offset;
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println!("{} => {}", offset, total);
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if seen.contains(&total) {
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println!("seen {} before", total);
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repeat = false;
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break;
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}
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seen.insert(total);
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}
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}
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println!("{}", total);
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Ok(())
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}
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