Finished Day 3-2

src/three/mod.rs

@@ -1,14 +1,54 @@
 use std::{str::FromStr, path::Path, option::Option};
 
+use itertools::Itertools;
+
 use crate::input::{AdventError, read_into_vec};
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Number {
     value: u32,
     position: u8,
     length: u8
 }
 
+#[derive(Debug, Clone)]
+pub struct Symbol {
+    position: u8,
+    symbol: char,
+}
+
+impl From<u8> for Symbol {
+    fn from(value: u8) -> Self {
+        Symbol{position: value, symbol: ' '}
+    }
+}
+
+impl PartialEq for Symbol {
+    fn eq(&self, other: &Self) -> bool {
+        self.position == other.position
+    }
+}
+
+impl PartialOrd for Symbol {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        match self.position.partial_cmp(&other.position) {
+            Some(core::cmp::Ordering::Equal) => {}
+            ord => return ord,
+        }
+        self.symbol.partial_cmp(&other.symbol)
+    }
+}
+
+impl Eq for Symbol {
+
+}
+
+impl Ord for Symbol {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.position.cmp(&other.position)
+    }
+}
+
 impl FromStr for RowInfo {
     type Err = AdventError;
 
@@ -25,7 +65,7 @@ impl FromStr for RowInfo {
 struct RowInfo {
     partial_start: Option<u8>,
     partial_number: Option<String>,
-    pub symbol_positions: Vec<u8>,
+    pub symbols: Vec<Symbol>,
     pub numbers: Vec<Number>,
 }
 
@@ -34,13 +74,13 @@ impl RowInfo {
         Self {
             partial_start: None,
             partial_number: None,
-            symbol_positions: Vec::<u8>::new(),
+            symbols: Vec::<Symbol>::new(),
             numbers: Vec::<Number>::new()
         }
     }
 
-    fn add_symbol(&mut self, i: usize) -> Result<(), AdventError> {
-        self.symbol_positions.push(i as u8);
+    fn add_symbol(&mut self, b: u8, i: usize) -> Result<(), AdventError> {
+        self.symbols.push(Symbol {position: i as u8, symbol: b as char});
         if self.partial_start != None {
             self.finish_digit(i)?
         }
@@ -61,7 +101,7 @@ impl RowInfo {
 
     fn process(&mut self, i: usize, b: &u8) -> Result<(), AdventError> {
         if b != &b'.' && !b.is_ascii_digit() {
-            self.add_symbol(i)?
+            self.add_symbol(*b, i)?
         }
         else if b.is_ascii_digit() {
             if self.partial_start.is_none() {
@@ -92,7 +132,7 @@ impl Default for RowInfo {
     }
 }
 
-pub fn gen_coords(y: usize, number: &Number) -> Vec<(u8, u8)> {
+pub fn gen_coords_number(y: usize, number: &Number) -> Vec<(u8, u8)> {
     let mut vec = Vec::<(u8, u8)>::new();
     let min_x = if number.position == 0 {
         0
@@ -112,17 +152,44 @@ pub fn gen_coords(y: usize, number: &Number) -> Vec<(u8, u8)> {
     vec
 }
 
+pub fn gen_coords_symbol(y: usize, symbol: &Symbol) -> Vec<(u8,u8)> {
+    let mut vec = Vec::<(u8, u8)>::new();
+    let min_x = if symbol.position == 0 {
+        0
+    } else {
+        symbol.position - 1
+    };
+    let max_x = symbol.position + 1 + 1;
+    for x in min_x..max_x {
+        if y != 0 {
+            vec.push((x, y as u8 - 1));
+        }
+        if x < symbol.position || x > symbol.position {
+            vec.push((x, y as u8));
+        }
+        vec.push((x, y as u8 + 1));
+    }
+    vec
+}
+
+fn filter_gears(rows: &mut Vec<RowInfo>) -> &mut Vec<RowInfo> {
+    for row in rows.iter_mut() {
+        row.symbols = row.symbols.clone().into_iter().filter(|x| { x.symbol == '*' }).collect::<Vec<Symbol>>()
+    }
+    rows
+}
+
 pub fn one() -> Result<(), AdventError> {
     let rows = read_into_vec::<RowInfo>(Path::new("resources/input3.txt"))?;
     let mut sum: u32 = 0;
     for (i, row) in rows.iter().enumerate() {
         for number in row.numbers.iter() {
-            let coords = gen_coords(i, number);
+            let coords = gen_coords_number(i, number);
             if coords.iter().any(|c| -> bool {
                 if c.1 as usize >= rows.len() {
                     false
                 } else {
-                    rows[c.1 as usize].symbol_positions.binary_search(&c.0).is_ok()
+                    rows[c.1 as usize].symbols.binary_search(&c.0.into()).is_ok()
                 }
             }) {
                 sum += number.value;
@@ -134,5 +201,35 @@ pub fn one() -> Result<(), AdventError> {
 }
 
 pub fn two() -> Result<(), AdventError> {
+    let mut rows = read_into_vec::<RowInfo>(Path::new("resources/input3.txt"))?;
+    rows = filter_gears(&mut rows).clone();
+    let mut sum: u32 = 0;
+    for (i, row) in rows.iter().enumerate() {
+        for symbol in row.symbols.iter() {
+            let coords = gen_coords_symbol(i, symbol);
+            let numbers = coords.iter().map(|(x, y)| {
+                if *y as usize >= rows.len() {
+                    None
+                } else {
+                    let relevant_numbers = rows[*y as usize].numbers.clone().into_iter().filter(|number| {*x >= number.position && *x < number.position + number.length}).collect::<Vec<Number>>();
+                    if relevant_numbers.len() == 1 {
+                        Some(relevant_numbers[0].clone())
+                    } else {
+                        None
+                    }
+                }
+            })
+            .filter(|x| {x.is_some()})
+            .map(|x| {x.unwrap()})
+            .unique()
+            .collect::<Vec<Number>>();
+
+            if numbers.len() == 2 {
+                sum += numbers[0].value * numbers[1].value;
+            }
+        }
+    }
+    println!("{}", sum);
+
     Ok(())
 }