finish 80

src/euler80/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "euler80"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rug = "*"

src/euler80/src/main.rs

@@ -0,0 +1,22 @@
+extern crate rug;
+
+use rug::Float;
+
+fn main() {
+    let mut result = 0;
+    for x in 2..=100 {
+        let two = Float::with_val(1024, x);
+        let root = two.sqrt();
+        let inner: u32 = root
+            .to_string()
+            .chars()
+            .filter(|c| *c != '.')
+            .take(100)
+            .map(|c| c.to_digit(10).unwrap())
+            .sum();
+        if inner > 50 {
+            result += inner;
+        }
+    }
+    println!("{result}");
+}