Implement 2025 - Day 3 - Part 2

2025/03.rs

@@ -28,48 +28,50 @@ fn main() {
     }).collect();
     println!("{:?}", raw_banks);
 
-    let banks: Vec<Bank> = raw_banks.iter().map(|rbank| {
-        Bank {
-            values: core::array::from_fn(|i| {
-                let i = i as u8;
-
-                let first = rbank.iter().enumerate().find_map(|(idx, v)| {
-                    (*v==i).then_some(idx)
-                })?;
-                let second = rbank.iter().enumerate().rev().find_map(|(idx, v)| {
-                    (*v==i).then_some(idx)
-                })?;
-
-                Some((first, second))
-            })
-        }
-    }).collect();
-    println!("{:?}", banks);
-
-    let mut result = 0;
-    for bank in banks.iter() {
+    let mut result = 0usize;
+    for bank in raw_banks.iter() {
         println!("{:?}", bank);
 
-        let iter_func = || bank.values.iter().enumerate().filter_map(|(idx, v)| {
-            let v = v.clone()?;
-            Some((idx, v))
-        });
+        let mut bank_iter = bank.iter();
+        let mut digits: Vec<_> = (&mut bank_iter).take(12).collect();
 
+        println!("Starting Digits {:?}", digits);
 
-        let value = iter_func().flat_map(|f| core::iter::repeat(f.clone()).zip(iter_func())).filter_map(|(first, second)| {
-            if !(first.1.0 < second.1.1) {
+        for other in bank_iter {
+            // println!("Looking to add {}", other);
+
+            let to_remove = digits.windows(2).enumerate().find_map(|(idx, window)| {
+                if window[0] >= window[1] {
                     return None;
                 }
 
-            let value = (first.0 * 10 + second.0) as usize;
-            // println!("{:?} - {:?} => {}", first, second, value);
+                Some(idx)
+            });
+            // dbg!(to_remove);
 
-            Some(value)
-        }).max().unwrap();
-        println!("{:?}", value);
-
-        result += value;
+            match to_remove {
+                Some(to_remove) => {
+                    digits.remove(to_remove);
+                    digits.push(other);
+                }
+                None => {
+                    if digits.last().copied().unwrap() < other {
+                        digits.pop();
+                        digits.push(other);   
+                    }
+                }
+            };
         }
 
-    println!("Result {:?}", result);
+        println!("Ending Digits {:?}", digits);
+
+        let bank_value = digits.iter().copied().rev().enumerate().fold(0usize, |acc, (idx, v)| {
+            acc + (*v as usize * 10usize.pow(idx as u32))
+        });
+        println!("Value {:?}", bank_value);
+
+        result += bank_value;
+    }
+
+    println!("Result: {:?}", result);
 }