pad numbers on directory names

day01/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day1"
+version = "0.1.0"

day01/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "day1"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

day01/src/main.rs

@@ -0,0 +1,32 @@
+use std::env;
+use std::fs::File;
+use std::io::BufReader;
+use std::io::BufRead;
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    let input = &args[1];
+    let reader = BufReader::new(File::open(input).expect("where file?"));
+
+    let (mut sum, mut max1, mut max2, mut max3) = (0, 0, 0, 0);
+    for line in reader.lines() {
+        if !line.as_ref().unwrap().trim().is_empty() {
+            sum += line.unwrap().parse::<i64>().unwrap();
+        } else {
+            println!("  {}? {} {} {}", sum, max1, max2, max3);
+            if sum > max1 {
+                max3 = max2;
+                max2 = max1;
+                max1 = sum;
+            } else if sum > max2 {
+                max3 = max2;
+                max2 = sum;
+            } else if sum > max3 {
+                max3 = sum;
+            }
+            sum = 0;
+        }
+    }
+
+    println!("Max3: {}", max1 + max2 + max3);
+}

day01/src/main1.rs

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+use std::env;
+use std::fs::File;
+use std::io::BufReader;
+use std::io::BufRead;
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    let input = &args[1];
+    let reader = BufReader::new(File::open(input).expect("where file?"));
+
+    let mut sum: i64 = 0;
+    let mut max: i64 = 0;
+    for line in reader.lines() {
+        if !line.as_ref().unwrap().trim().is_empty() {
+            sum += line.unwrap().parse::<i64>().unwrap();
+        } else {
+            if sum > max {
+                max = sum;
+            }
+            sum = 0;
+        }
+    }
+
+    println!("Max: {}", max);
+}

day01/test.txt

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+1000
+2000
+3000
+
+4000
+
+5000
+6000
+
+7000
+8000
+9000
+
+10000
+