59 lines
1.2 KiB
Rust
59 lines
1.2 KiB
Rust
use std::fs::File;
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use std::io;
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use std::io::BufRead;
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use std::io::BufReader;
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pub fn part1() -> io::Result<u32> {
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let file = File::open("input/day1")?;
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let reader = BufReader::new(file);
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let mut first = true;
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let mut previous = 0;
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let mut count = 0;
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for line in reader.lines() {
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let num: u32 = line?.parse().unwrap();
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if !first && num > previous {
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count += 1;
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}
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previous = num;
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first = false;
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}
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Ok(count)
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}
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pub fn part2() -> io::Result<u32> {
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let file = File::open("input/day1")?;
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let reader = BufReader::new(file);
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let mut vals: [u32; 3] = [0, 0, 0];
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let mut count = 0;
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for (i, line) in reader.lines().enumerate() {
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let num: u32 = line?.parse().unwrap();
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if i < 3 {
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vals[i] = num;
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} else {
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// Calculate the previous sum
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let sum = vals[0] + vals[1] + vals[2];
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// Shift the values
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vals[0] = vals[1];
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vals[1] = vals[2];
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vals[2] = num;
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let new_sum = vals[0] + vals[1] + vals[2];
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if new_sum > sum {
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count += 1;
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}
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}
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}
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Ok(count)
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}
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