day 10 part 1

src/bin/10.rs

@@ -0,0 +1,87 @@
+advent_of_code::solution!(10);
+
+use itertools::Itertools;
+use bitvec::{bitvec, vec::BitVec};
+
+fn parse_line(line: &str) -> Option<(BitVec, Vec<BitVec>, Vec<usize>)>{
+    let fields = line.split(' ').collect_vec();
+    let goal: BitVec = fields[0].chars().filter_map(|c| {
+        match c {
+            '.' => Some(false),
+            '#' => Some(true),
+            _ => None
+        }
+    }).collect();
+    // println!("{goal:?}");
+
+    let buttons = fields[1..fields.len()-1].iter().map(|b| {
+        let mut button_flag = bitvec![0; 10]; // BitVec::with_capacity(10);
+        let buttons = &b[1..b.len()-1];
+
+        // println!("{buttons:?}");
+        for v in buttons.split(',').map(|v| v.parse::<usize>().unwrap()) {
+            // println!("{v}");
+            button_flag.insert(v, true);
+        }
+        button_flag
+    }).collect_vec();
+    let joltage_str = fields[fields.len()-1];
+    let joltage = joltage_str[1..joltage_str.len()-1].split(',').map(|j| j.parse::<usize>().unwrap()).collect_vec();
+
+    Some((goal, buttons, joltage))
+}
+
+pub fn part_one(input: &str) -> Option<u64> {
+    let mut total_key_presses = 0;
+    for line in input.lines().filter(|l| !l.is_empty()) {
+        let (goal, buttons, _) = parse_line(line).unwrap();
+        // println!("goal: {goal:?}");
+        // println!("buttons ({}): {buttons:?}", buttons.len());
+        // println!("result: {result}");
+
+        // cycle through all permutations of button presses
+        let mut least_presses = u32::MAX;
+        for ii in 0..2_usize.pow(buttons.len() as u32) {
+            let mut state = goal.clone();
+
+            for (bidx, b) in buttons.iter().enumerate() {
+                if ii >> bidx & 1 == 1 {
+                    state ^= b;
+                }
+            }
+
+            // println!("new state {state}");
+            if state.count_ones() == 0 {
+                let key_presses = ii.count_ones();
+                // println!("Found solution in {key_presses} key presses!");
+                if key_presses < least_presses {
+                    least_presses = key_presses
+                }
+            }
+        }
+        total_key_presses += least_presses;
+    }
+
+    Some(total_key_presses as u64)
+}
+
+pub fn part_two(input: &str) -> Option<u64> {
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(7));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+}