Implement 2025 - Day 3 - Part 1

2025/03.rs

@@ -0,0 +1,75 @@
+---cargo
+---
+
+static CONTENT: &'static str = include_str!("./inputs/03_1.txt");
+
+#[derive(Debug)]
+struct Bank {
+    values: [Option<(usize, usize)>; 10],
+}
+
+fn main() {
+    let raw_banks: Vec<Vec<u8>> = CONTENT.lines().map(|l| l.trim()).filter(|l| !l.is_empty()).map(|l| {
+        l.chars().map(|c| {
+            match c {
+                '0' => 0,
+                '1' => 1,
+                '2' => 2,
+                '3' => 3,
+                '4' => 4,
+                '5' => 5,
+                '6' => 6,
+                '7' => 7,
+                '8' => 8,
+                '9' => 9,
+                c => unreachable!("Other {:?}", c),
+            }
+        }).collect::<Vec<u8>>()
+    }).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() {
+        println!("{:?}", bank);
+
+        let iter_func = || bank.values.iter().enumerate().filter_map(|(idx, v)| {
+            let v = v.clone()?;
+            Some((idx, v))
+        });
+       
+        
+        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) {
+                return None;
+            }
+
+            let value = (first.0 * 10 + second.0) as usize;
+            // println!("{:?} - {:?} => {}", first, second, value);
+
+            Some(value)
+        }).max().unwrap();
+        println!("{:?}", value);
+
+        result += value;
+    }
+
+    println!("Result {:?}", result);
+}