Part 06

src/bin/part06.rs

@@ -0,0 +1,87 @@
+use std::time;
+
+
+#[derive(Debug)]
+struct Race {
+    time: u64,
+    distance: u64,
+}
+
+impl Race {
+    fn get_boundaries(&self) -> (u32, u32) {
+        let sqrt = ((self.time * self.time - 4 * self.distance) as f64).sqrt() / 2.0;
+        let t1 = (self.time as f64 / 2.0) - sqrt + 0.0001;
+        let t2 = (self.time as f64 / 2.0) + sqrt - 0.0001;
+        (t1.ceil() as u32, t2.floor() as u32)
+    }
+
+    fn get_num_of_solutions(&self) -> u32 {
+        let (t1, t2) = self.get_boundaries();
+        t2 - t1 + 1
+    }
+}
+
+fn main() {
+    println!("PART 1");
+
+    let s1 = time::Instant::now();
+    let races = load_input_part1();
+    let d1 = s1.elapsed();
+    println!("Load: {:?}", d1);
+    
+    let s2 = time::Instant::now();
+    let num_solutions = races.iter().map(|r| r.get_num_of_solutions()).collect::<Vec<_>>();
+    let d2 = s2.elapsed();
+    println!("Num-Solutions: {:?} in {:?}", num_solutions, d2);
+
+    let s3 = time::Instant::now();
+    let result: u32 = num_solutions.iter().map(|n| *n as u32).product();
+    let d3 = s3.elapsed();
+    println!("Result: {} in {:?}", result, d3);
+
+    println!("PART 2");
+
+    let race = load_input_part2();
+    let s4 = time::Instant::now();
+    let num_solutions = race.get_num_of_solutions();
+    let d4 = s4.elapsed();
+    println!("Num-Solutions: {:?} in {:?}", num_solutions, d4);
+
+    println!("Total: {:?}", d1 + d2 + d3 + d4);
+}
+
+fn load_input_part1() -> Vec<Race> {
+    let mut races: Vec<Race> = Vec::new();
+
+    let data = std::fs::read_to_string("src/bin/part06.txt")
+                                .expect("Could not read file");
+    let mut lines = data.lines();
+
+    let times = lines.next().unwrap().split_whitespace().skip(1).map(|s| s.parse::<u64>().unwrap()).collect::<Vec<_>>();
+    let distances = lines.next().unwrap().split_whitespace().skip(1).map(|s| s.parse::<u64>().unwrap()).collect::<Vec<_>>();
+
+    for (i, t) in times.iter().enumerate() {
+        races.push(
+            Race {
+                time: *t,
+                distance: distances[i]
+            }
+        )
+    }
+
+    races
+}
+
+fn load_input_part2() -> Race {
+    let data = std::fs::read_to_string("src/bin/part06.txt")
+                                .expect("Could not read file");
+    let mut lines = data.lines();
+
+    let time = lines.next().unwrap().split_whitespace().skip(1).fold(String::new(), |acc, x| acc.to_owned() + x).parse::<u64>().unwrap();
+    let distance = lines.next().unwrap().split_whitespace().skip(1).fold(String::new(), |acc, x| acc.to_owned() + x).parse::<u64>().unwrap();
+
+    Race {
+        time,
+        distance
+    }
+}

src/bin/part06.sample

@@ -0,0 +1,2 @@
+Time:      7  15   30
+Distance:  9  40  200

src/bin/part06.txt

@@ -0,0 +1,2 @@
+Time:        61     70     90     66
+Distance:   643   1184   1362   1041