day 1

.gitignore

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+input.txt

d1/.gitignore

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+/target

d1/Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "d1"
+version = "0.1.0"

d1/Cargo.toml

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+[package]
+name = "d1"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

d1/src/main.rs

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+use std::fs::read_to_string;
+use std::io::Error;
+
+fn main() -> Result<(), Error> {
+    let mut max = 0;
+    let mut all = Vec::new();
+    let mut current = 0;
+
+    for line in read_to_string("input.txt")?.split("\n") {
+        if line == "" {
+            if current >= max {
+                max = current
+            }
+            all.push(current);
+            current = 0
+        } else {
+            current += line.parse::<u32>().unwrap()
+        }
+    }
+    if current >= max {
+        max = current
+    }
+    all.push(current);
+
+    all.sort_by(|a, b| b.cmp(a));
+
+    println!("part 1: {}", max);
+    println!("part 2: {}", all.iter().take(3).sum::<u32>());
+
+    Ok(())
+}