diff --git a/Cargo.lock b/Cargo.lock
index e40da41..f39ebe1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -26,11 +26,23 @@ dependencies = [
  "dhat",
  "fmt",
  "itertools",
+ "memoize",
  "pico-args",
  "regex",
  "tinyjson",
 ]
 
+[[package]]
+name = "ahash"
+version = "0.7.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "891477e0c6a8957309ee5c45a6368af3ae14bb510732d2684ffa19af310920f9"
+dependencies = [
+ "getrandom 0.2.15",
+ "once_cell",
+ "version_check",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.3"
@@ -226,7 +238,18 @@ checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi",
+ "wasi 0.9.0+wasi-snapshot-preview1",
+]
+
+[[package]]
+name = "getrandom"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4567c8db10ae91089c99af84c68c38da3ec2f087c3f82960bcdbf3656b6f4d7"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.11.0+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -235,6 +258,15 @@ version = "0.31.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "07e28edb80900c19c28f1072f2e8aeca7fa06b23cd4169cefe1af5aa3260783f"
 
+[[package]]
+name = "hashbrown"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
+dependencies = [
+ "ahash",
+]
+
 [[package]]
 name = "iana-time-zone"
 version = "0.1.61"
@@ -311,12 +343,44 @@ version = "0.4.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
 
+[[package]]
+name = "lru"
+version = "0.7.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e999beba7b6e8345721bd280141ed958096a2e4abdf74f67ff4ce49b4b54e47a"
+dependencies = [
+ "hashbrown",
+]
+
 [[package]]
 name = "memchr"
 version = "2.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
+[[package]]
+name = "memoize"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5df4051db13d0816cf23196d3baa216385ae099339f5d0645a8d9ff2305e82b8"
+dependencies = [
+ "lazy_static",
+ "lru",
+ "memoize-inner",
+]
+
+[[package]]
+name = "memoize-inner"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "27bdece7e91f0d1e33df7b46ec187a93ea0d4e642113a1039ac8bfdd4a3273ac"
+dependencies = [
+ "lazy_static",
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "miniz_oxide"
 version = "0.8.0"
@@ -424,7 +488,7 @@ version = "0.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "de0737333e7a9502c789a36d7c7fa6092a49895d4faa31ca5df163857ded2e9d"
 dependencies = [
- "getrandom",
+ "getrandom 0.1.16",
  "redox_syscall 0.1.57",
  "rust-argon2",
 ]
@@ -511,7 +575,7 @@ checksum = "ad1e866f866923f252f05c889987993144fb74e722403468a4ebd70c3cd756c0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -538,6 +602,17 @@ version = "1.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"
 
+[[package]]
+name = "syn"
+version = "1.0.109"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.90"
@@ -578,12 +653,24 @@ version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "adb9e6ca4f869e1180728b7950e35922a7fc6397f7b641499e8f3ef06e50dc83"
 
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
 [[package]]
 name = "wasi"
 version = "0.9.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
 
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+
 [[package]]
 name = "wasm-bindgen"
 version = "0.2.97"
@@ -606,7 +693,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
  "wasm-bindgen-shared",
 ]
 
@@ -628,7 +715,7 @@ checksum = "98c9ae5a76e46f4deecd0f0255cc223cfa18dc9b261213b8aa0c7b36f61b3f1d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 1c79ddb..e0e1866 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,6 +27,7 @@ clippy = "0.0.302"
 dhat = { version = "0.3.3", optional = true }
 fmt = "0.1.0"
 itertools = "0.13.0"
+memoize = "0.4.2"
 pico-args = "0.5.0"
 regex = "1.11.1"
 tinyjson = "2.5.1"
diff --git a/src/bin/11.rs b/src/bin/11.rs
index 70852e3..545bd85 100644
--- a/src/bin/11.rs
+++ b/src/bin/11.rs
@@ -1,42 +1,63 @@
 advent_of_code::solution!(11);
 
-use std::iter::successors;
+use memoize::memoize;
 
-fn update_stones(stones: &Vec<u64>) -> Vec<u64> {
-    stones.into_iter().flat_map(|st|
-        match (st, st.checked_ilog10().unwrap_or(0) + 1) {
-            (0, _) => vec![1],
-            (n, digits) if digits % 2 == 0 && digits > 0 => {
-                let div = 10u64.pow(digits / 2);
-                vec![
-                    n / div,
-                    n % div,
-                ]
-            },
-            _ => vec![st * 2024],
+#[memoize]
+fn get_child_stones_count(stone: u64, depth: u8) -> usize {
+    if depth == 0 {
+        return 1;
+    }
+    let digits = stone.checked_ilog10().unwrap_or(0) + 1;
+    match (stone, digits) {
+        (0, _) => get_child_stones_count(1, depth - 1),
+        (n, digits) if digits % 2 == 0 && digits > 0 => {
+            let div = 10u64.pow(digits / 2);
+            get_child_stones_count(n / div, depth - 1) + get_child_stones_count(n % div, depth - 1)
         }
-    ).collect()
+        _ => get_child_stones_count(stone * 2024, depth - 1),
+    }
 }
 
+// fn update_stones(stones: &Vec<u64>) -> Vec<u64> {
+//     stones.into_iter().flat_map(|st|
+//         match (st, st.checked_ilog10().unwrap_or(0) + 1) {
+//             (0, _) => vec![1],
+//             (n, digits) if digits % 2 == 0 && digits > 0 => {
+//                 let div = 10u64.pow(digits / 2);
+//                 vec![
+//                     n / div,
+//                     n % div,
+//                 ]
+//             },
+//             _ => vec![st * 2024],
+//         }
+//     ).collect()
+// }
+
 fn parse_input(input: &str) -> Result<Vec<u64>, std::num::ParseIntError> {
     input.split_whitespace().map(|c| c.parse::<u64>()).collect()
 }
 
 pub fn part_one(input: &str) -> Option<usize> {
-    let stones = parse_input(input).ok()?;
-    successors(Some(stones), |st| Some(update_stones(st)))
-        .nth(25)
-        .unwrap()
-        .len()
+    parse_input(input)
+        .ok()?
+        .into_iter()
+        .map(|st| get_child_stones_count(st, 25))
+        .sum::<usize>()
         .into()
+    // successors(Some(stones), |st| Some(update_stones(st)))
+    //     .nth(25)
+    //     .unwrap()
+    //     .len()
+    //     .into()
 }
 
 pub fn part_two(input: &str) -> Option<usize> {
-    let stones = parse_input(input).ok()?;
-    successors(Some(stones), |st| Some(update_stones(st)))
-        .nth(75)
-        .unwrap()
-        .len()
+    parse_input(input)
+        .ok()?
+        .into_iter()
+        .map(|st| get_child_stones_count(st, 75))
+        .sum::<usize>()
         .into()
 }