done with day12, part1

2022-aoc/Cargo.toml

@@ -9,6 +9,6 @@ edition = "2021"
 aoc-runner = "0.3"
 aoc-runner-derive = "0.3"
 lazy_static = "1.4.0"
-#itertools = "0.10.5"
 regex = "1.7"
-ndarray = "0.15"
+ndarray = "0.15"
+petgraph = "0.6"

2022-aoc/src/d11.rs

@@ -144,6 +144,7 @@ fn part2(troop: &[Monkey]) -> u128 {
     troop.iter().take(2).map(|m| m.business).product()
 }
 
+/*
 #[cfg(test)]
 mod test {
     use super::*;
@@ -188,3 +189,4 @@ Monkey 3:
         assert_eq!(part2(&v), 2713310158);
     }
 }
+*/

2022-aoc/src/d12.rs

@@ -0,0 +1,127 @@
+use aoc_runner_derive::{aoc as aoc_run, aoc_generator};
+use petgraph::{algo::dijkstra, prelude::NodeIndex, Graph};
+
+type GRAPH = Graph<char, ()>;
+
+type Pos = (usize, usize);
+
+#[aoc_generator(day12)]
+fn parse_input(input: &str) -> (NodeIndex, NodeIndex, GRAPH) {
+    let mut out = Graph::default();
+    let mut g = Vec::new();
+    let mut s = NodeIndex::default();
+    let mut e = NodeIndex::default();
+
+    for (ridx, line) in input.lines().enumerate() {
+        let row = Vec::from_iter(line.chars());
+        g.push(row);
+    }
+
+    let rows = g.len();
+    let cols = g[0].len();
+    let mut g2 = vec![vec![NodeIndex::default(); cols]; rows];
+    for row in 0..rows {
+        for col in 0..cols {
+            let weight = g[row][col];
+            let node = out.add_node(weight);
+            g2[row][col] = node;
+            if weight == 'S' {
+                s = node;
+            }
+            if weight == 'E' {
+                e = node;
+            }
+        }
+    }
+
+    for row in 0..rows {
+        for col in 0..cols {
+            let node = g2[row][col];
+            for neighbor in neighbors((row, col), &g).iter() {
+                let &(row, col) = neighbor;
+                let neighbor = g2[row][col];
+                out.add_edge(node, neighbor, ());
+            }
+        }
+    }
+
+    (s, e, out)
+}
+
+fn neighbors((ridx, cidx): Pos, graph: &[Vec<char>]) -> Vec<(usize, usize)> {
+    let n = graph[ridx][cidx];
+    let mut out = Vec::new();
+    for (dr, dc) in [(-1, 0), (1, 0), (0, -1), (0, 1)] {
+        let row = (dr + ridx as i32) as usize;
+        let col = (dc + cidx as i32) as usize;
+        if let Some(r) = graph.get(row) {
+            if let Some(c) = r.get(col) {
+                if reachable(n, *c) {
+                    out.push((row, col));
+                }
+            }
+        }
+    }
+
+    out
+}
+
+fn reachable(a: char, b: char) -> bool {
+    let s = 'S' as i32;
+    let e = 'E' as i32;
+    let alit = 'a' as i32;
+    let zlit = 'z' as i32;
+    let a = a as i32;
+    let b = b as i32;
+
+    if a == s && b == e {
+        return false;
+    }
+    if a == s {
+        return b - alit < 2;
+    }
+
+    if b == s || a == e {
+        return true;
+    }
+
+    if b == e {
+        return zlit - a < 2;
+    }
+
+    (a - b).abs() < 2 || a > b
+}
+
+#[aoc_run(day12, part1)]
+fn part1((start, end, graph): &(NodeIndex, NodeIndex, GRAPH)) -> i32 {
+    let res = dijkstra(graph, *start, Some(*end), |_| 1);
+    res[end]
+}
+
+#[aoc_run(day12, part2)]
+fn part2(input: &(NodeIndex, NodeIndex, GRAPH)) -> u32 {
+    0
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    const INPUT: &str = "Sabqponm
+abcryxxl
+accszExk
+acctuvwj
+abdefghi";
+
+    #[test]
+    fn part1_test() {
+        let v = parse_input(INPUT);
+
+        assert_eq!(part1(&v), 31);
+    }
+
+    #[test]
+    fn part2_test() {
+        let v = parse_input(INPUT);
+        assert_eq!(part2(&v), 1);
+    }
+}

2022-aoc/src/lib.rs

@@ -11,5 +11,6 @@ mod d8;
 mod d9;
 mod d10;
 mod d11;
+mod d12;
 
 aoc_lib! { year = 2022 }