005 ok

005/solution.rs

@@ -0,0 +1,23 @@
+fn gcd(a: i32, b: i32) -> i32 {
+    let mut max = a.max(b);
+    let mut min = a.min(b);
+    loop {
+        let res = max % min;
+        if res == 0 { return min; }
+        max = min;
+        min = res;
+    }
+}
+
+fn main() {
+    let n = 20;
+    let mut p = 1;
+
+    for k in 1..=n {
+        let q = gcd(p, k);
+        let m = k / q;
+        p *= m;
+        println!("{} -> {}", k, p);
+    }
+
+}