aoc2022 day09 part one

src/aoc2022/day09/mod.rs

@@ -0,0 +1,168 @@
+use std::collections::HashMap;
+
+fn move_tail(head: &(isize, isize), mut tail: (isize, isize)) -> (isize, isize) {
+    if head.0 == tail.0 && head.1 == tail.1 {
+        // same spot, wich is fine
+    } else if head.1 == tail.1 {
+        // x coords are different -> horizontal movement
+        if tail.0 + 2 == head.0 {
+            tail.0 = tail.0 + 1;
+        } else if tail.0 - 2 == head.0 {
+            tail.0 = tail.0 - 1;
+        }
+    } else if head.0 == tail.0 {
+        // y coords are different  -> vertical movement
+        if tail.1 + 2 == head.1 {
+            tail.1 = tail.1 + 1;
+        } else if tail.1 - 2 == head.1 {
+            tail.1 = tail.1 - 1;
+        }
+    } else {
+        // both coords are different -> horizontal and vertical movement
+        if head.0 == tail.0 + 1 {
+            if head.1 == tail.1 + 2 {
+                tail.0 = tail.0 + 1;
+                tail.1 = tail.1 + 1;
+            } else if head.1 == tail.1 - 2 {
+                tail.0 = tail.0 + 1;
+                tail.1 = tail.1 - 1;
+            }
+        } else if head.0 == tail.0 - 1 {
+            if head.1 == tail.1 + 2 {
+                tail.0 = tail.0 - 1;
+                tail.1 = tail.1 + 1;
+            } else if head.1 == tail.1 - 2 {
+                tail.0 = tail.0 - 1;
+                tail.1 = tail.1 - 1;
+            }
+        } else if head.0 == tail.0 + 2 {
+            if head.1 == tail.1 + 1 {
+                tail.0 = tail.0 + 1;
+                tail.1 = tail.1 + 1;
+            } else if head.1 == tail.1 - 1 {
+                tail.0 = tail.0 + 1;
+                tail.1 = tail.1 - 1;
+            }
+        } else if head.0 == tail.0 - 2 {
+            if head.1 == tail.1 + 1 {
+                tail.0 = tail.0 - 1;
+                tail.1 = tail.1 + 1;
+            } else if head.1 == tail.1 - 1 {
+                tail.0 = tail.0 - 1;
+                tail.1 = tail.1 - 1;
+            }
+        }
+    }
+
+    tail
+}
+pub fn task_one(input: &str) -> String {
+    let mut visited_places: HashMap<(isize, isize), u8> = HashMap::new();
+    let mut head = (0, 0);
+    let mut tail = (0, 0);
+
+    visited_places.insert(tail, 0);
+
+    for line in input.trim().lines() {
+        match line.split_once(" ").unwrap() {
+            ("U", count) => {
+                for _ in 1..=count.parse::<usize>().unwrap() {
+                    head.1 = head.1 + 1;
+
+                    tail = move_tail(&head, tail);
+
+                    visited_places.insert(tail, 0);
+                }
+            }
+            ("R", count) => {
+                for _ in 1..=count.parse::<usize>().unwrap() {
+                    head.0 = head.0 + 1;
+
+                    tail = move_tail(&head, tail);
+
+                    visited_places.insert(tail, 0);
+                }
+            }
+            ("D", count) => {
+                for _ in 1..=count.parse::<usize>().unwrap() {
+                    head.1 = head.1 - 1;
+
+                    tail = move_tail(&head, tail);
+
+                    visited_places.insert(tail, 0);
+                }
+            }
+            ("L", count) => {
+                for _ in 1..=count.parse::<usize>().unwrap() {
+                    head.0 = head.0 - 1;
+
+                    tail = move_tail(&head, tail);
+
+                    visited_places.insert(tail, 0);
+                }
+            }
+            (_, _) => panic!(),
+        }
+    }
+
+    visited_places.len().to_string()
+}
+
+pub fn task_two(input: &str) -> String {
+    let mut visited_places: HashMap<(isize, isize), u8> = HashMap::new();
+    let mut knots: [(isize, isize); 10] = [(0, 0); 10];
+
+    visited_places.insert(knots[9], 0);
+
+    for line in input.trim().lines() {
+        match line.split_once(" ").unwrap() {
+            ("U", count) => {
+                for _ in 1..=count.parse::<usize>().unwrap() {
+                    knots[0].1 = knots[0].1 + 1;
+
+                    for i in 1..10 {
+                        knots[i] = move_tail(&knots[i - 1], knots[i]);
+                    }
+
+                    visited_places.insert(knots[9], 0);
+                }
+            }
+            ("R", count) => {
+                for _ in 1..=count.parse::<usize>().unwrap() {
+                    knots[0].0 = knots[0].0 + 1;
+
+                    for i in 1..10 {
+                        knots[i] = move_tail(&knots[i - 1], knots[i]);
+                    }
+
+                    visited_places.insert(knots[9], 0);
+                }
+            }
+            ("D", count) => {
+                for _ in 1..=count.parse::<usize>().unwrap() {
+                    knots[0].1 = knots[0].1 - 1;
+
+                    for i in 1..10 {
+                        knots[i] = move_tail(&knots[i - 1], knots[i]);
+                    }
+
+                    visited_places.insert(knots[9], 0);
+                }
+            }
+            ("L", count) => {
+                for _ in 1..=count.parse::<usize>().unwrap() {
+                    knots[0].0 = knots[0].0 - 1;
+
+                    for i in 1..10 {
+                        knots[i] = move_tail(&knots[i - 1], knots[i]);
+                    }
+
+                    visited_places.insert(knots[9], 0);
+                }
+            }
+            (_, _) => panic!(),
+        }
+    }
+
+    visited_places.len().to_string()
+}

src/aoc2022/mod.rs

@@ -6,3 +6,4 @@ pub mod day05;
 pub mod day06;
 pub mod day07;
 pub mod day08;
+pub mod day09;

src/main.rs

@@ -60,4 +60,7 @@ fn main() {
 
     puzzle = Puzzle { day: 8, year: 2022, task_one: aoc2022::day08::task_one, task_two: aoc2022::day08::task_two };
     puzzle.solve_and_print();
+
+    puzzle = Puzzle { day: 9, year: 2022, task_one: aoc2022::day09::task_one, task_two: aoc2022::day09::task_two };
+    puzzle.solve_and_print();
 }