Move Rust exercises in a subdirectory

1 files changed, 15 insertions, 0 deletions

diff --git a/rust/armstrong-numbers/src/lib.rs b/rust/armstrong-numbers/src/lib.rs
new file mode 100644
index 0000000..41b0824
--- /dev/null
+++ b/rust/armstrong-numbers/src/lib.rs
@@ -0,0 +1,15 @@
+
+fn digits(mut n: u32) -> (usize,Vec<u32>) {
+    let mut v = vec![];
+    while n > 9 {
+        v.push(n % 10);
+        n /= 10;
+    }
+    v.push(n);
+    (v.len(),v)
+}
+
+pub fn is_armstrong_number(num: u32) -> bool {
+    let (l,v) = digits(num);
+    v.iter().map(|x| x.pow(l as u32)).sum::<u32>() == num
+}