Data update

Task/Fibonacci-sequence/Rust/fibonacci-sequence-4.rs

@@ -0,0 +1,9 @@
+fn fib_tail_recursive(nth: usize) -> usize {
+  fn fib_tail_iter(n: usize, prev_fib: usize, fib: usize) -> usize {
+    match n {
+      0 => prev_fib,
+      n => fib_tail_iter(n - 1, fib, prev_fib + fib),
+    }
+  }
+  fib_tail_iter(nth, 0, 1)
+}