done with part2

2022-aoc/src/d12.rs

@@ -12,7 +12,7 @@ fn parse_input(input: &str) -> (NodeIndex, NodeIndex, GRAPH) {
     let mut s = NodeIndex::default();
     let mut e = NodeIndex::default();
 
-    for (ridx, line) in input.lines().enumerate() {
+    for line in input.lines() {
         let row = Vec::from_iter(line.chars());
         g.push(row);
     }
@@ -99,8 +99,22 @@ fn part1((start, end, graph): &(NodeIndex, NodeIndex, GRAPH)) -> i32 {
 }
 
 #[aoc_run(day12, part2)]
-fn part2(input: &(NodeIndex, NodeIndex, GRAPH)) -> u32 {
-    0
+fn part2((start, end, graph): &(NodeIndex, NodeIndex, GRAPH)) -> i32 {
+    let mut roots = Vec::new();
+    roots.push(*start);
+    for (i, w) in graph.node_weights().enumerate() {
+        if w == &'a' {
+            roots.push(NodeIndex::new(i));
+        }
+    }
+    let mut res = Vec::with_capacity(roots.len());
+    for root in roots {
+        let p = dijkstra(graph, root, Some(*end), |_| 1);
+        if let Some(v) = p.get(end) {
+            res.push(*v)
+        }
+    }
+    *res.iter().min().unwrap()
 }
 
 #[cfg(test)]
@@ -122,6 +136,6 @@ abdefghi";
     #[test]
     fn part2_test() {
         let v = parse_input(INPUT);
-        assert_eq!(part2(&v), 1);
+        assert_eq!(part2(&v), 29);
     }
 }