Data update

Task/Stern-Brocot-sequence/Rust/stern-brocot-sequence.rs

@@ -0,0 +1,38 @@
+use gcd::Gcd;
+
+fn stern_brocot(up_to: u64) -> Vec<u64> {
+    let mut seq = vec![1_u64, 1];
+    let mut last = 1_u64;
+    let mut idx = 1_usize;
+    while last < up_to {
+        last = seq[idx];
+        seq.push(last + seq[idx - 1]);
+        seq.push(last);
+        idx += 1;
+    }
+    seq
+}
+
+fn test_stern_brocot() {
+    let seq = stern_brocot(100);
+    println!("First 15 in sequence: {:?}", &seq[0..15]);
+    println!("First positions of integers 1 through 10:");
+    for i in 1..=10 {
+        match seq.iter().position(|n| *n == i) {
+            Some(idx) => println!("    {:>2} at position {}", i, idx + 1),
+            _ => eprintln!("Error finding position of {}", i),
+        }
+    }
+    println!(
+        "   100 at position {}",
+        seq.iter().position(|n| *n == 100).unwrap_or(0) + 1
+    );
+    println!(
+        "The first 999 consecutive pairs have gcd of 1: {}.",
+        (1..1000).all(|i| seq[i - 1].gcd(seq[i]) == 1)
+    );
+}
+
+fn main() {
+    test_stern_brocot();
+}