finish 34

src/euler34/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "euler34"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

src/euler34/src/main.rs

@@ -0,0 +1,45 @@
+use std::collections::HashMap;
+
+fn main() {
+    let mut hm = HashMap::new();
+    for i in 0..10 {
+        hm.insert(i, factorial(i));
+    }
+
+    let mut result = vec![];
+
+    for i in 3..1_000_000_u64 {
+        if i.to_digits()
+            .iter()
+            .map(|d| hm.get(d).unwrap())
+            .sum::<u64>()
+            == i
+        {
+            result.push(i);
+        };
+    }
+    println!("{}", result.iter().sum::<u64>())
+}
+
+fn factorial(x: u64) -> u64 {
+    if x == 0 {
+        1
+    } else if x == 1 {
+        x
+    } else {
+        x * factorial(x - 1)
+    }
+}
+
+trait ToDigits {
+    fn to_digits(&self) -> Vec<u64>;
+}
+
+impl ToDigits for u64 {
+    fn to_digits(&self) -> Vec<u64> {
+        self.to_string()
+            .chars()
+            .map(|c| c.to_digit(10).unwrap() as u64)
+            .collect()
+    }
+}