From 0fa3d7fe5a27b87bcffb89fb30ffd294a0c2c40a Mon Sep 17 00:00:00 2001
From: Federico I <git@federicoigne.com>
Date: Sun, 29 Mar 2020 21:14:32 +0100
Subject: [rust] Armstrong Numbers

---
 armstrong-numbers/src/lib.rs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 armstrong-numbers/src/lib.rs

(limited to 'armstrong-numbers/src/lib.rs')

diff --git a/armstrong-numbers/src/lib.rs b/armstrong-numbers/src/lib.rs
new file mode 100644
index 0000000..41b0824
--- /dev/null
+++ b/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
+}
-- 
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