initial commit

day2/.gitignore

@@ -0,0 +1 @@
+/target

day2/Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day2"
+version = "0.1.0"

day2/Cargo.toml

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+[package]
+name = "day2"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

day2/src/main.rs

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+use std::fs::File;
+use std::io::{self, BufRead};
+use std::path::Path;
+
+fn main() {
+    let mut safe_reports = 0;
+    let mut safe_reports_with_dampener = 0;
+    if let Ok(lines) = read_lines("input") {
+        for line in lines.flatten() {
+            let report = line.trim().split(' ').flat_map(str::parse::<i32>).collect::<Vec<_>>();
+            if check_report(&report) {
+                safe_reports += 1;
+                safe_reports_with_dampener += 1;
+            }
+            else {
+                for i in 0..report.len() {
+                    let mut new_report = report.to_vec();
+                    new_report.remove(i);
+                    if check_report(&new_report) {
+                        safe_reports_with_dampener += 1;
+                        break;
+                    }
+                }
+            }
+        }
+    }
+    println!("Number of safe reports: {}", safe_reports);
+    println!("Number of safe reports (with dampener): {}", safe_reports_with_dampener);
+}
+
+fn check_report(report: &Vec<i32>) -> bool {
+    let mut inc_or_dec:i32 = 0;
+    for i in 0..report.len() - 1 {
+        let diff = report[i+1] - report[i];
+        println!("diff is {}", diff);
+        if (inc_or_dec < 0 && diff > 0) || (inc_or_dec > 0 && diff < 0) { 
+            return false;
+        }
+        inc_or_dec = diff;
+        if diff.abs() < 1 || diff.abs() > 3 {
+            return false;
+        }
+    }
+    return true;
+}
+
+fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
+where P: AsRef<Path>, {
+    let file = File::open(filename)?;
+    Ok(io::BufReader::new(file).lines())
+}