day 3 part one

qqrm · Dec 30, 2023 · 4741c48 · 4741c48
1 parent e519967
commit 4741c48
Showing 1 changed file with 73 additions and 14 deletions.
diff --git a/day3/part_one.rs b/day3/part_one.rs
@@ -11,30 +11,89 @@ fn main() -> io::Result<()> {
     let file = File::open(&path)?;
     let mut sum = 0;
 
-    let mut matrix = vec![vec![' '; SIZE]; SIZE]; // Initialize a 140x140 matrix with spaces
+    let mut matrix = [[b' '; SIZE]; SIZE]; // Initialize a 140x140 matrix with spaces
 
-    for (i, line) in io::BufReader::new(file).lines().enumerate() {
-        if i >= SIZE {
-            break; // Only read the first 140 lines
+    for (i, line) in io::BufReader::new(file).lines().enumerate().take(SIZE) {
+        for (j, ch) in line?.chars().enumerate().take(SIZE) {
+            matrix[i][j] = ch as u8;
         }
+    }
+
+    for (y, row) in matrix.iter().enumerate() {
+        let mut buf = vec![];
+        let mut num_buf = String::new();
 
-        let line = line?;
-        for (j, ch) in line.chars().enumerate().take(SIZE) {
-            matrix[i][j] = ch;
+        for (x, &ch) in row.iter().enumerate() {
+            if ch.is_ascii_alphanumeric() {
+                num_buf.push(ch as char);
+                buf.push((x as i64, y as i64));
+            }
+
+            if !ch.is_ascii_alphanumeric() || x == SIZE - 1 {
+                if !buf.is_empty() {
+                    let contour = extract_contour(&buf);
+                    let number: i32 = num_buf.parse().unwrap_or(0);
+                    sum += contour.iter().any(|&(cx, cy)| matrix[cy as usize][cx as usize] != b'.') as i32 * number;
+                    buf.clear();
+                    num_buf.clear();
+                }
+            }
         }
     }
 
-    // print_matrix(&matrix);
-
     println!("Total sum: {}", sum);
     Ok(())
 }
 
-fn print_matrix(matrix: &Vec<Vec<char>>) {
-    for row in matrix {
-        for &ch in row {
-            print!("{}", ch);
+fn extract_contour(buf: &[(i64, i64)]) -> Vec<(i64, i64)> {
+    let mut circle = vec![];
+    let mut visited = std::collections::HashSet::new();
+
+    for &(x, y) in buf {
+        for &(nx, ny) in &get_neighbors(x, y) {
+            if nx >= 0 && ny >= 0 && nx < SIZE as i64 && ny < SIZE as i64 
+                && !buf.contains(&(nx, ny)) && visited.insert((nx, ny)) {
+                    circle.push((nx, ny));
+            }
         }
-        println!(); // Print a new line at the end of each row
     }
+
+    circle
+}
+
+fn get_neighbors(x: i64, y: i64) -> [(i64, i64); 8] {
+    [
+        (x - 1, y), (x + 1, y), (x, y - 1), (x, y + 1),
+        (x - 1, y - 1), (x + 1, y - 1), (x - 1, y + 1), (x + 1, y + 1),
+    ]
+}
+
+fn print_contour(coords: &Vec<(i64, i64)>, matrix: &[[char; SIZE]; SIZE]) {
+    // Find the minimum and maximum x and y coordinates
+    let min_x = coords.iter().map(|&(x, _)| x).min().unwrap() as usize;
+    let max_x = coords.iter().map(|&(x, _)| x).max().unwrap() as usize;
+    let min_y = coords.iter().map(|&(_, y)| y).min().unwrap() as usize;
+    let max_y = coords.iter().map(|&(_, y)| y).max().unwrap() as usize;
+
+    // Iterate over the specified contour area and print the relevant part of the matrix
+    for i in min_y..=max_y {
+        for j in min_x..=max_x {
+            // Check if the coordinate is within the bounds of the matrix
+            if i < SIZE && j < SIZE {
+                print!("{}", matrix[i][j]);
+            } else {
+                print!(" "); // Print a space if outside the matrix bounds
+            }
+        }
+        println!(); // New line at the end of each row
+    }
+    println!(); // New line at the end of each row
+}
+
+fn wait_for_enter() {
+    println!("Press Enter to continue...");
+    let mut input = String::new();
+    io::stdin()
+        .read_line(&mut input)
+        .expect("Failed to read line");
 }