Initial commit

1 files changed, 78 insertions, 0 deletions

diff --git a/d08/src/main.rs b/d08/src/main.rs
new file mode 100644
index 0000000..cbdd1fd
--- /dev/null
+++ b/d08/src/main.rs
@@ -0,0 +1,78 @@
+use std::fs;
+
+fn solve_puzzle(lines: &Vec<&str>) -> [[bool; 6]; 50] {
+    let mut pixels = [[false; 6]; 50];
+
+    for line in lines {
+        let words: Vec<&str> = line.split_ascii_whitespace().collect();
+        if words[0] == "rect" {
+            // Read operation parameters
+            let wxh: Vec<&str> = words[1].split('x').collect();
+            let w: usize = wxh[0].parse().unwrap();
+            let h: usize = wxh[1].parse().unwrap();
+
+            // Apply operation to state
+            for x in 0..w {
+                for y in 0..h {
+                    pixels[x][y] = true;
+                }
+            }
+        } else if words[0] == "rotate" && words[1] == "row" {
+            // Read operation parameters
+            let which: Vec<&str> = words[2].split('=').collect();
+            let y: usize = which[1].parse().unwrap();
+            let n: usize = words[4].parse().unwrap();
+
+            // Apply operation to state
+            let mut old = Vec::new();
+            for x in 0..50 {
+                old.push(pixels[x][y]);
+            }
+            for x in 0..50 {
+                pixels[x][y] = old[(x + 50 - n) % 50];
+            }
+        } else if words[0] == "rotate" && words[1] == "column" {
+            // Read operation parameters
+            let which: Vec<&str> = words[2].split('=').collect();
+            let x: usize = which[1].parse().unwrap();
+            let n: usize = words[4].parse().unwrap();
+
+            // Apply operation to state
+            let old = pixels[x];
+            for y in 0..6 {
+                pixels[x][y] = old[(y + 6 - n) % 6];
+            }
+        }
+    }
+
+    pixels
+}
+
+fn main() {
+    let input = fs::read_to_string("input.txt").unwrap();
+    let lines = input.lines().collect();
+
+    let pixels = solve_puzzle(&lines);
+
+    // Part 2 must be read by eye, gives "UPOJFLBCEZ" for me
+    println!("Part 2 solution:");
+    let mut total = 0;
+    for y in 0..6 {
+        print!("\t");
+        for x in 0..50 {
+            print!(
+                "{}",
+                if pixels[x][y] {
+                    total += 1;
+                    '#'
+                } else {
+                    ' '
+                }
+            );
+        }
+        print!("\n");
+    }
+
+    // Part 1 gives 116 for me
+    println!("Part 1 solution: {}", total);
+}