Forgot to commit day 12 part 1 done

2022/rust/src/day12.rs

@@ -0,0 +1,161 @@
+use std::collections::HashMap;
+use std::collections::HashSet;
+
+mod common;
+
+type Input = (Vec<Vec<u8>>, (usize, usize), (usize, usize));
+type Answer = usize;
+
+fn processed_input(input: &str) -> Input {
+    let mut result = vec![];
+    let mut start = (0, 0);
+    let mut end = (0, 0);
+    let lines = input
+        .lines()
+        .map(|l| l.to_string())
+        .collect::<Vec<String>>();
+    for y in 0..lines.len() {
+        let mut row = vec![];
+        let chars = lines[y].chars().collect::<Vec<char>>();
+        for x in 0..chars.len() {
+            match chars[x] {
+                'S' => {
+                    row.push(0);
+                    start = (y, x);
+                }
+                'E' => {
+                    row.push(25);
+                    end = (y, x);
+                }
+                c => row.push(c as u8 - 'a' as u8),
+            }
+        }
+        result.push(row)
+    }
+    return (result, start, end);
+}
+
+fn part1(input: &Input) -> Answer {
+    let mut open_set = HashSet::<(usize, usize)>::from([input.1]);
+    let mut came_from = HashMap::<(usize, usize), (usize, usize)>::new();
+    let mut cheapest_for = HashMap::<(usize, usize), i64>::from([(input.1, 0)]);
+    let mut guess_score = HashMap::<(usize, usize), i64>::from([(input.1, 0)]);
+
+    let h = input.0.len();
+    let w = input.0[0].len();
+
+    // guess_score.get(&(y, x)).unwrap_or(&i64::MAX).clone()
+    while open_set.len() > 0 {
+        let (mut y, mut x) = open_set
+            .iter()
+            .min_by(|(y1, x1), (y2, x2)| {
+                guess_score
+                    .get(&(*y1, *x1))
+                    .unwrap_or(&i64::MAX)
+                    .cmp(&guess_score.get(&(*y2, *x2)).unwrap_or(&i64::MAX))
+            })
+            .unwrap();
+
+        if (y, x) == input.2 {
+            let mut n = 0;
+            while let Some((ny, nx)) = came_from.get(&(y, x)) {
+                y = *ny;
+                x = *nx;
+                n += 1;
+            }
+            return n;
+        }
+
+        open_set.remove(&(y, x));
+        let c = input.0[y][x];
+        let mut potential_neighbors = vec![];
+        if y > 0 {
+            potential_neighbors.push((y - 1, x));
+        }
+        if y < h - 1 {
+            potential_neighbors.push((y + 1, x));
+        }
+        if x > 0 {
+            potential_neighbors.push((y, x - 1));
+        }
+        if x < w - 1 {
+            potential_neighbors.push((y, x + 1));
+        }
+        for (ny, nx) in potential_neighbors
+            .iter()
+            .filter(|(y, x)| (input.0[*y][*x] as i32) - (c as i32) <= 1)
+        {
+            let ny = ny.clone();
+            let nx = nx.clone();
+            let score = guess_score.get(&(y, x)).unwrap_or(&i64::MAX).clone() + 1;
+            let ns = guess_score.get(&(ny, nx)).unwrap_or(&i64::MAX).clone();
+            if score < ns {
+                came_from.insert((ny, nx), (y, x));
+                guess_score.insert((ny, nx), score);
+                cheapest_for.insert((ny, nx), score + 1);
+                open_set.insert((ny, nx));
+            }
+        }
+    }
+
+    let mut distances: Vec<Vec<usize>> = vec![];
+    let mut previous_bests: Vec<Vec<Option<(usize, usize)>>> = vec![];
+    for y in 0..input.0.len() {
+        let mut row_distances = vec![];
+        let mut row_previous_bests = vec![];
+        for _ in 0..input.0[y].len() {
+            row_distances.push(std::usize::MAX);
+            row_previous_bests.push(None);
+        }
+        distances.push(row_distances);
+        previous_bests.push(row_previous_bests);
+    }
+    distances[input.1 .0][input.1 .1] = 0;
+
+    // no path found
+    usize::MAX
+}
+
+fn part2(input: &Input) -> Answer {
+    let mut possible_starts = HashSet::<(usize, usize)>::from([input.1]);
+    for y in 0..input.0.len() {
+        for x in 0..input.0[y].len() {
+            if input.0[y][x] == 0 {
+                possible_starts.insert((y, x));
+            }
+        }
+    }
+    possible_starts.iter().map(|s| part1((input.0, s, input.2))
+    }
+}
+
+fn main() {
+    let input_text = common::day_input(12);
+    eprintln!("{}\n\nAbove is your input file.\n\n", input_text);
+    let input = processed_input(&input_text);
+    common::show_answers(&part1(&input), &part2(&input))
+    // common::show_both_answers(&both_parts(&input))
+}
+
+// fn both_parts(input: &Input) -> (Answer, Answer) {
+//     (0, 0)
+// }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const TEST_INPUT: &str = "Sabqponm
+abcryxxl
+accszExk
+acctuvwj
+abdefghi";
+
+    #[test]
+    fn test() {
+        let input = processed_input(TEST_INPUT);
+        assert_eq!(part1(&input), 31);
+        assert_eq!(part2(&input), 0);
+        // assert_eq!(both_parts(&input), (0, 0));
+    }
+}