improve day10

1 files changed, 6 insertions, 16 deletions

diff --git a/2024/day10.rs b/2024/day10.rs
index 7c8576d..ffe9f00 100644
--- a/2024/day10.rs
+++ b/2024/day10.rs
@@ -29,35 +29,26 @@ fn dfs(x0: i64, y0: i64, map: &Vec<Vec<i64>>, mut hs: HashSet<(i64, i64)>) -> Ha
     return hs;
 }
 
-fn dfs2(
-    x0: i64,
-    y0: i64,
-    map: &Vec<Vec<i64>>,
-    mut path: Vec<(i64, i64)>,
-    mut hs: HashSet<Vec<(i64, i64)>>,
-) -> HashSet<Vec<(i64, i64)>> {
-    //println!("{} {}", x0, y0);
+fn dfs2(x0: i64, y0: i64, map: &Vec<Vec<i64>>) -> i64 {
     let h = map.len() as i64;
     let w = map[0].len() as i64;
 
-    path.push((x0, y0));
-
     let n = map[y0 as usize][x0 as usize];
     if n == 9 {
-        hs.insert(path);
-        return hs;
+        return 1;
     }
 
+    let mut score = 0;
     for (dx, dy) in [(0, 1), (0, -1), (1, 0), (-1, 0)] {
         let x = x0 + dx as i64;
         let y = y0 + dy as i64;
         if (0 <= x) && (x < w) && (0 <= y) && (y < h) {
             if map[y as usize][x as usize] == n + 1 {
-                hs = dfs2(x, y, map, path.clone(), hs);
+                score += dfs2(x, y, map);
             }
         }
     }
-    return hs;
+    return score;
 }
 
 fn main() {
@@ -92,8 +83,7 @@ fn main() {
         let hs = dfs(x0, y0, &map, HashSet::new());
         res1 += hs.len();
 
-        let hs2 = dfs2(x0, y0, &map, Vec::new(), HashSet::new());
-        res2 += hs2.len();
+        res2 += dfs2(x0, y0, &map);
     }
 
     println!("res1: {}", res1);