Data commit

Task/Successive-prime-differences/Rust/successive-prime-differences.rust

@@ -0,0 +1,47 @@
+fn is_prime(num: u32) -> bool {
+  match num {
+      x if x < 4 => x > 1,
+      x if x % 2 == 0 => false,
+      x => { let limit = (x as f32).sqrt().ceil() as u32;
+              (3..=limit).step_by(2).all(|a| x % a != 0)
+            }
+  }
+}
+
+fn primes_by_diffs(primes: &[u32], diffs: &[u32]) -> Vec<Vec<u32>> {
+
+  fn select(diffs: &[u32], prime_win: &[u32], acc: bool) -> bool {
+    if diffs.is_empty() || !acc {
+      acc
+    }
+    else {
+      let acc1 = prime_win[0] + diffs[0] == prime_win[1];
+      select(&diffs[1..], &prime_win[1..], acc1)
+    }
+  }
+
+  primes.windows(diffs.len() + 1)
+        .filter(|&win| select(diffs, win, true))
+        .map(|win| win.to_vec())
+        .collect()
+}
+
+fn main() {
+  let limit = 1_000_000u32;
+  let start = std::time::Instant::now();
+  let primes = (2..).filter(|&i| is_prime(i));
+  let prime_list: Vec<u32> = primes.take_while(|&p| p <= limit).collect();
+  let duration = start.elapsed();
+  println!("primes time: {:?}", duration);
+  for diffs in vec!(vec!(1), vec!(2), vec!(2,2), vec!(2,4), vec!(4,2), vec!(6,4,2), vec!(2,4,6)) {
+    let result_list = primes_by_diffs(&prime_list, &diffs);
+    let len = result_list.len();
+    println!("{:?} number: {}\n\tfirst: {:?}", diffs, len, result_list[0]);
+    if len == 1 {
+      println!()
+    }
+    if len > 1 {
+      println!("\tlast: {:?}\n", result_list.last().unwrap())
+    }
+  }
+}