1 files changed, 90 insertions, 0 deletions
diff --git a/08/src/part-2.rs b/08/src/part-2.rs
new file mode 100644
index 0000000..94bf4d5
--- /dev/null
+++ b/08/src/part-2.rs
@@ -0,0 +1,90 @@
+mod tensor;
+
+use std::cmp::{max};
+use std::io::{BufRead};
+
+use tensor::{Index, Shape, Tensor};
+
+fn main() {
+    let stdin = std::io::stdin();
+    let mut handle = stdin.lock();
+
+    let mut tmp: Vec<usize> = Vec::new();
+    let mut m: usize = 0;
+    let mut n: usize = 0;
+    let mut n_check: usize = 0;
+    
+    loop {
+        let buf = handle.fill_buf().expect("IO error");
+        let bytes_read = buf.len();
+        if bytes_read == 0 { break; }
+
+        for & b in buf.into_iter() {
+            if b >= b'0' && b <= b'9' {
+                tmp.push((b - b'0').try_into().unwrap());
+                if m == 0 {
+                    n += 1;
+                }
+                n_check += 1;
+            }
+            if b == b'\n' {
+                m += 1;
+                assert_eq!(n_check, n);
+                n_check = 0;
+            }
+        }
+
+        handle.consume(bytes_read);
+    }
+
+    let mut x: Tensor<usize, 2> = Tensor::new_from([m, n], tmp);
+    let shape = x.shape().clone();
+
+    let mut highest_score: usize = 0;
+
+    for i in 0..m {
+        for j in 0..n {
+            let h = x[[i, j]];
+            
+            // Look north
+            let mut north_dist = 0;
+            for a in (0..i).rev() {
+                north_dist += 1;
+                if x[[a, j]] >= h {
+                    break;
+                }
+            }
+
+            // Look south.
+            let mut south_dist = 0;
+            for a in i+1..m {
+                south_dist += 1;
+                if x[[a, j]] >= h {
+                    break;
+                }
+            }
+
+            // Look east.
+            let mut east_dist = 0;
+            for a in j+1..n {
+                east_dist += 1;
+                if x[[i, a]] >= h {
+                    break;
+                }
+            }
+
+            // Look west.
+            let mut west_dist = 0;
+            for a in (0..j).rev() {
+                west_dist += 1;
+                if x[[i, a]] >= h {
+                    break;
+                }
+            }
+
+            highest_score = max(highest_score, north_dist*south_dist*east_dist*west_dist);
+        }
+    }
+
+    println!("{}", highest_score);
+}