Data commit

Task/Fibonacci-sequence/Rust/fibonacci-sequence-1.rust

@@ -0,0 +1,11 @@
+fn main() {
+    let mut prev = 0;
+    // Rust needs this type hint for the checked_add method
+    let mut curr = 1usize;
+
+    while let Some(n) = curr.checked_add(prev) {
+        prev = curr;
+        curr = n;
+        println!("{}", n);
+    }
+}

Task/Fibonacci-sequence/Rust/fibonacci-sequence-2.rust

@@ -0,0 +1,12 @@
+use std::mem;
+fn main() {
+    fibonacci(0,1);
+}
+
+fn fibonacci(mut prev: usize, mut curr: usize) {
+    mem::swap(&mut prev, &mut curr);
+    if let Some(n) = curr.checked_add(prev) {
+        println!("{}", n);
+        fibonacci(prev, n);
+    }
+}

Task/Fibonacci-sequence/Rust/fibonacci-sequence-3.rust

@@ -0,0 +1,7 @@
+fn fib(n: u32) -> u32 {
+    match n {
+        0 => 0,
+        1 => 1,
+        n => fib(n - 1) + fib(n - 2),
+    }
+}

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

@@ -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)
+}

Task/Fibonacci-sequence/Rust/fibonacci-sequence-5.rust

@@ -0,0 +1,13 @@
+fn main() {
+    for num in fibonacci_sequence() {
+        println!("{}", num);
+    }
+}
+
+fn fibonacci_sequence() -> impl Iterator<Item = u64> {
+    let sqrt_5 = 5.0f64.sqrt();
+    let p = (1.0 + sqrt_5) / 2.0;
+    let q = 1.0 / p;
+    // The range is sufficient up to 70th Fibonacci number
+    (0..1).chain((1..70).map(move |n| ((p.powi(n) + q.powi(n)) / sqrt_5 + 0.5) as u64))
+}

Task/Fibonacci-sequence/Rust/fibonacci-sequence-6.rust

@@ -0,0 +1,29 @@
+use std::mem;
+
+struct Fib {
+    prev: usize,
+    curr: usize,
+}
+
+impl Fib {
+    fn new() -> Self {
+        Fib {prev: 0, curr: 1}
+    }
+}
+
+impl Iterator for Fib {
+    type Item = usize;
+    fn next(&mut self) -> Option<Self::Item>{
+        mem::swap(&mut self.curr, &mut self.prev);
+        self.curr.checked_add(self.prev).map(|n| {
+            self.curr = n;
+            n
+        })
+    }
+}
+
+fn main() {
+    for num in Fib::new() {
+        println!("{}", num);
+    }
+}

Task/Fibonacci-sequence/Rust/fibonacci-sequence-7.rust

@@ -0,0 +1,4 @@
+fn main() {
+    std::iter::successors(Some((1u128, 0)), |&(a, b)| a.checked_add(b).map(|s| (b, s)))
+        .for_each(|(_, u)| println!("{}", u));
+}