diff --git a/src/day11.rs b/src/day11.rs
index badde4b..1a521c6 100644
--- a/src/day11.rs
+++ b/src/day11.rs
@@ -3,72 +3,49 @@
  * Author: Adam Jeniski; @Ajetski
  */
 
-type Data = Vec<Vec<u8>>;
+fn part_1_solution(mut input: Vec<Vec<i32>>) -> u64 {
+    fn flash(data: &mut Vec<Vec<i32>>, row: usize, col: usize, count: &mut u64) {
+        *count += 1;
+        //println!("flash {row} {col}");
+        data[row][col] = 0;
 
-fn parse_input(input: &str) -> Data {
-    input
-        .split_ascii_whitespace()
-        .map(|s| s.chars().map(|c| c.to_string().parse().unwrap()).collect())
-        .collect()
-}
+        for (i, j) in (-1i32..=1).flat_map(|i| (-1i32..=1).map(move |j| (i, j))) {
+            // compute coords as i32 so we can do bounds checking
+            let x = i + row as i32;
+            let y = j + col as i32;
+            //print!("{row}, {col}; {x}, {y}. ");
 
-fn flash(data: &mut Data, row: usize, col: usize) {
-    data[row][col] += 1;
-    if row > 0 && col > 0 {
-        data[row - 1][col - 1] += 1;
-    }
-    if row > 0 {
-        data[row - 1][col] += 1;
-    }
-    if row > 0 && col < data[row].len() - 1 {
-        data[row - 1][col + 1] += 1;
-    }
-    if col < data[row].len() - 1 {
-        data[row][col + 1] += 1;
-    }
-    if row < data.len() - 1 && col < data[row].len() - 1 {
-        data[row + 1][col + 1] += 1;
-    }
-    if row < data.len() - 1 {
-        data[row + 1][col] += 1;
-    }
-    if row < data.len() - 1 && col > 0 {
-        data[row + 1][col - 1] += 1;
-    }
-    if col > 0 {
-        data[row][col - 1] += 1;
-    }
-}
+            // skip out of bounds
+            if x < 0 || y < 0 || x >= data.len() as i32 || y >= data[x as usize].len() as i32 {
+                //println!("exiting");
+                continue;
+            }
 
-fn part_1_solution(input: &str) -> u64 {
-    let mut data = parse_input(input);
+            // convert coords to usize for easy indexing
+            let x = x as usize;
+            let y = y as usize;
+
+            if data[x][y] != 0 {
+                data[x][y] += 1;
+                //println!("updated data to {}", data[x][y]);
+            }
+            if data[x][y] > 9 {
+                //println!("flushing");
+                flash(data, x, y, count);
+            }
+        }
+    }
     let mut count = 0;
-
     for _ in 0..100 {
-        // increase energy
-        for row in 0..data.len() {
-            for col in 0..data[row].len() {
-                data[row][col] += 1;
+        for row in &mut input {
+            for cell in row {
+                *cell += 1;
             }
         }
-
-        // while any flashable cells exits; flash them
-        while data.iter().any(|row| row.iter().any(|cell| *cell == 10)) {
-            for row in 0..data.len() {
-                for col in 0..data[row].len() {
-                    if data[row][col] == 10 {
-                        flash(&mut data, row, col);
-                    }
-                }
-            }
-        }
-
-        // count all the flashed cells and reset them to zero
-        for row in 0..data.len() {
-            for col in 0..data[row].len() {
-                if data[row][col] > 9 {
-                    data[row][col] = 0;
-                    count += 1;
+        for i in 0..input.len() {
+            for j in 0..input[i].len() {
+                if input[i][j] > 9 {
+                    flash(&mut input, i, j, &mut count);
                 }
             }
         }
@@ -76,37 +53,89 @@ fn part_1_solution(input: &str) -> u64 {
     count
 }
 
+fn part_2_solution(mut input: Vec<Vec<i32>>) -> u64 {
+    fn flash(data: &mut Vec<Vec<i32>>, row: usize, col: usize) {
+        //println!("flash {row} {col}");
+        data[row][col] = 0;
+
+        for (i, j) in (-1i32..=1).flat_map(|i| (-1i32..=1).map(move |j| (i, j))) {
+            // compute coords as i32 so we can do bounds checking
+            let x = i + row as i32;
+            let y = j + col as i32;
+            //print!("{row}, {col}; {x}, {y}. ");
+
+            // skip out of bounds
+            if x < 0 || y < 0 || x >= data.len() as i32 || y >= data[x as usize].len() as i32 {
+                //println!("exiting");
+                continue;
+            }
+
+            // convert coords to usize for easy indexing
+            let x = x as usize;
+            let y = y as usize;
+
+            if data[x][y] != 0 {
+                data[x][y] += 1;
+                //println!("updated data to {}", data[x][y]);
+            }
+            if data[x][y] > 9 {
+                //println!("flushing");
+                flash(data, x, y);
+            }
+        }
+    }
+    for count in 1..100000 {
+        for row in &mut input {
+            for cell in row {
+                *cell += 1;
+            }
+        }
+        for i in 0..input.len() {
+            for j in 0..input[i].len() {
+                if input[i][j] > 9 {
+                    flash(&mut input, i, j);
+                }
+            }
+        }
+        if input.iter().all(|row| row.iter().all(|cell| cell == &0)) {
+            return count;
+        }
+    }
+    todo!()
+}
+
 #[cfg(test)]
 mod part1 {
     use super::*;
+    fn parse_input(input: &str) -> Vec<Vec<i32>> {
+        input
+            .split_ascii_whitespace()
+            .map(|s| s.chars().map(|c| c.to_string().parse().unwrap()).collect())
+            .collect()
+    }
 
     #[test]
-    fn run_sample() {
+    fn day_11_sample_part_one() {
         let input = include_str!("../inputs/11_test.txt");
-        let sol = part_1_solution(input);
+        let sol = part_1_solution(parse_input(input));
         assert_eq!(sol, 1656);
     }
 
-    // #[test]
-    // fn run() {
-    //     let input = include_str!("../inputs/11.txt");
-    //     assert_eq!(part_1_solution(input), 339477);
-    // }
+    #[test]
+    fn day_11_test_part_one() {
+        let input = include_str!("../inputs/11.txt");
+        assert_eq!(part_1_solution(parse_input(input)), 1725);
+    }
+
+    #[test]
+    fn day_11_sample_part_two() {
+        let input = include_str!("../inputs/11_test.txt");
+        assert_eq!(part_2_solution(parse_input(input)), 195);
+    }
+
+    #[test]
+    fn day_11_test_part_two() {
+        let input = include_str!("../inputs/11.txt");
+        assert_eq!(part_2_solution(parse_input(input)), 308);
+    }
 }
-
-// #[cfg(test)]
-// mod part2 {
-//     use super::*;
-
-//     #[test]
-//     fn run_sample() {
-//         let input = include_str!("../inputs/11_test.txt");
-//         assert_eq!(part_2_solution(input), 288957);
-//     }
-
-//     #[test]
-//     fn run() {
-//         let input = include_str!("../inputs/11.txt");
-//         assert_eq!(part_2_solution(input), 3049320156);
-//     }
-// }