init

problems/p43/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "p43"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

problems/p43/src/main.rs

@@ -0,0 +1,40 @@
+fn solve() -> u64 {
+    let mut digits = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+    let mut sum = 0;
+    loop {
+        if digits[0] != 0 && check_property(&digits) {
+            sum += digits.iter().fold(0u64, |acc, &d| acc * 10 + d as u64);
+        }
+        if !next_permutation(&mut digits) {
+            break;
+        }
+    }
+    sum
+}
+
+fn next_permutation<T: Ord>(array: &mut [T]) -> bool {
+    let i = match array.windows(2).rposition(|w| w[0] < w[1]) {
+        Some(i) => i,
+        None => return false,
+    };
+    let j = array.iter().rposition(|x| x > &array[i]).unwrap();
+    array.swap(i, j);
+    array[i + 1..].reverse();
+    true
+}
+
+fn check_property(d: &[i32]) -> bool {
+    let primes = [2, 3, 5, 7, 11, 13, 17];
+    for i in 0..7 {
+        let num = (d[i + 1] * 100 + d[i + 2] * 10 + d[i + 3]) as u64;
+        if !num.is_multiple_of(primes[i]) {
+            return false;
+        }
+    }
+    true
+}
+fn main() {
+    let sum = solve();
+
+    println!("{sum}");
+}