43

src/euler43/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "euler43"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+itertools = "0.14.0"

src/euler43/src/main.rs

@@ -0,0 +1,45 @@
+use itertools::Itertools;
+
+fn main() {
+    let numbers = generate_pandigital_numbers();
+
+    let mut sum = 0;
+    for number in numbers {
+        if satisfies_divisibility_rules(&number) {
+            sum += number.parse::<usize>().unwrap();
+        }
+    }
+    println!("{sum}");
+}
+
+fn generate_pandigital_numbers() -> Vec<String> {
+    ('0'..='9')
+        .permutations(10)
+        .map(|c| c.iter().collect())
+        .collect()
+}
+
+fn satisfies_divisibility_rules(s: &str) -> bool {
+    let n1: usize = extract(s, 1, 3);
+    let n2: usize = extract(s, 2, 4);
+    let n3: usize = extract(s, 3, 5);
+    let n4: usize = extract(s, 4, 6);
+    let n5: usize = extract(s, 5, 7);
+    let n6: usize = extract(s, 6, 8);
+    let n7: usize = extract(s, 7, 9);
+    n1 % 2 == 0
+        && n2 % 3 == 0
+        && n3 % 5 == 0
+        && n4 % 7 == 0
+        && n5 % 11 == 0
+        && n6 % 13 == 0
+        && n7 % 17 == 0
+}
+
+fn extract(s: &str, min: usize, max_inclusive: usize) -> usize {
+    s.chars()
+        .get(min..=max_inclusive)
+        .collect::<String>()
+        .parse()
+        .unwrap()
+}