finished day07

README.md

@@ -1,23 +1,23 @@
 # Advent of Code 2025
 ```bash
-day01:A =>            1150  (    56us)
-day01:B =>            1150  (    55us)
-day02:A =>     31839939622  (  7769us)
-day02:B =>     41662374059  ( 64866us)
-day03:A =>           16812  (    81us)
-day03:B => 166345822896410  (   275us)
-day04:A =>            1518  (   195us)
-day04:B =>            8665  (  3720us)
-day05:A =>             701  (   139us)
+day01:A =>            1150  (    49us)
+day01:B =>            1150  (    47us)
+day02:A =>     31839939622  (  7731us)
+day02:B =>     41662374059  ( 64732us)
+day03:A =>           16812  (    84us)
+day03:B => 166345822896410  (   286us)
+day04:A =>            1518  (   202us)
+day04:B =>            8665  (  3737us)
+day05:A =>             701  (   140us)
 day05:B => 352340558684863  (    19us)
-day06:A =>   6503327062445  (   194us)
-day06:B =>   9640641878593  (   132us)
-day07:A =>               0  (     0us)
-day07:B =>               0  (     0us)
+day06:A =>   6503327062445  (   207us)
+day06:B =>   9640641878593  (   133us)
+day07:A =>            1678  (    49us)
+day07:B => 357525737893560  (    55us)
 day08:A =>               0  (     0us)
 day08:B =>               0  (     0us)
-day09:A =>      4725826296  (   162us)
+day09:A =>      4725826296  (   164us)
 day09:B =>               0  (     0us)
                             ----------
-                              78285us
+                              81857us
 ```

src/day07/mod.rs

@@ -23,14 +23,12 @@ mod tests {
 ...............";
 
     #[test]
-    #[ignore]
     fn part07a() {
         assert_eq!(part07a::solve(PUZZLE.to_string()), 21);
     }
 
     #[test]
-    #[ignore]
     fn part07b() {
-        assert_eq!(part07b::solve(PUZZLE.to_string()), 0);
+        assert_eq!(part07b::solve(PUZZLE.to_string()), 40);
     }
 }

src/day07/part07a.rs

@@ -1,4 +1,29 @@
 
 pub fn solve(puzzle: String) -> u64 {
-    0 // TODO
+    let mut solution = 0;
+    let mut lines = puzzle.lines();
+    let mut source = lines
+        .next()
+        .unwrap()
+        .chars()
+        .map(|c| match c { 'S' => 1, _ => 0 } )
+        .collect::<Vec<u8>>();
+
+    lines.for_each(|line| {
+        let mut next_source = source.clone();
+        line.chars().zip(source.iter()).enumerate().for_each(|(i, x)| {
+            match x {
+                ('^', 1) => {
+                    solution += 1;
+                    next_source[i-1] = 1;
+                    next_source[i] = 0;
+                    next_source[i+1] = 1;
+                },
+                _ => (),
+            }
+        });
+        source = next_source;
+    });
+
+     solution
 }

src/day07/part07b.rs

@@ -1,4 +1,29 @@
 
 pub fn solve(puzzle: String) -> u64 {
-    0 // TODO
+    let mut solution = 0;
+    let mut lines = puzzle.lines();
+    let mut source = lines
+        .next()
+        .unwrap()
+        .chars()
+        .map(|c| match c { 'S' => (1, 1), _ => (0, 0) } )
+        .collect::<Vec<(u8, u64)>>();
+
+    lines.for_each(|line| {
+        let mut next_source = source.clone();
+        line.chars().zip(source.iter()).enumerate().for_each(|(i, x)| {
+            match x {
+                ('^', (1, weight)) => {
+                    solution += weight;
+                    next_source[i-1] = (1 , next_source[i-1].1 + weight);
+                    next_source[i] = (0, 0);
+                    next_source[i+1] = (1 , next_source[i+1].1 + weight)
+                },
+                _ => (),
+            }
+        });
+        source = next_source;
+    });
+
+    solution + 1
 }