finish 32

src/euler32/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "euler32"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

src/euler32/src/main.rs

@@ -0,0 +1,42 @@
+use std::collections::HashSet;
+
+type Int = u64;
+
+fn main() {
+    let f: Vec<_> = (1..10_000_u64)
+        .filter(|n| {
+            let s = n.to_string();
+            let hs = s.chars().collect::<HashSet<_>>();
+            hs.len() == s.len() && !hs.contains(&'0')
+        })
+        .collect();
+
+    let mut result = HashSet::new();
+    for f1 in &f {
+        for f2 in f.iter().rev() {
+            let p = f1 * f2;
+            if are_pandigital([f1, f2, &p]) {
+                println!("{f1} {f2} {p}");
+                result.insert(p);
+            }
+        }
+    }
+    println!("{}", result.iter().sum::<u64>());
+}
+
+fn are_pandigital(input: [&Int; 3]) -> bool {
+    let mut accum = HashSet::new();
+    let mut length = 0;
+    for n in input {
+        let s = n.to_string();
+        length += s.len();
+        let hs = s.chars().collect::<HashSet<_>>();
+        if s.len() != hs.len() {
+            return false;
+        }
+        for item in hs {
+            accum.insert(item);
+        }
+    }
+    accum.len() == 9 && length == 9 && !accum.contains(&'0')
+}