finished 49

euler49/src/main.rs

@@ -5,6 +5,7 @@ const MIN_VALUE: Int = 2;
 const MAX_VALUE: Int = 10_000;
 const SIZE: usize = (MAX_VALUE - MIN_VALUE) as usize;
 type Array = [bool; SIZE];
+type Solution = [Int; 3];
 
 fn main() {
     println!("Getting prime numbers up to {}", MAX_VALUE);
@@ -51,13 +52,13 @@ impl Primes {
     }
 }
 
-fn find_using_iter(primes: &Primes) -> [Int; 3] {
+fn find_using_iter(primes: &Primes) -> Solution {
     for p1 in primes.vector.iter() {
         let p2 = p1 + 3330;
         let p3 = p2 + 3330;
         if primes.set.contains(&p2) && primes.set.contains(&p3) {
             let candidate = [*p1, p2, p3];
-            if satisfies_checks(&candidate) {
+            if satisfies_checks(&candidate) && candidate[0] != 1487 {
                 return candidate;
             }
         }
@@ -65,13 +66,12 @@ fn find_using_iter(primes: &Primes) -> [Int; 3] {
     panic!()
 }
 
-fn satisfies_checks(cand: &[Int; 3]) -> bool {
-    cand.iter()
-        .map(|x| get_amount_of_digits(x))
-        .filter(|x, y| x == y)
+fn satisfies_checks(candidates: &Solution) -> bool {
+    let vec: Vec<_> = candidates.iter().map(get_amount_of_digits).collect();
+    vec[0] == vec[1] && vec[0] == vec[2]
 }
 
-fn get_amount_of_digits(x: Int) -> HashMap<i32, usize> {
+fn get_amount_of_digits(x: &Int) -> HashMap<i32, usize> {
     let mut map = get_new_map();
     x.to_string()
         .chars()
@@ -85,3 +85,36 @@ fn get_amount_of_digits(x: Int) -> HashMap<i32, usize> {
 fn get_new_map() -> HashMap<i32, usize> {
     (0..=9).into_iter().zip([0; 10]).collect()
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::{get_amount_of_digits, get_new_map, satisfies_checks, Solution};
+
+    #[test]
+    fn test_get_amount_of_digits() {
+        let x = 4731;
+        let hs = get_amount_of_digits(&x);
+        let mut reference = get_new_map();
+        reference.insert(4, 1);
+        reference.insert(7, 1);
+        reference.insert(3, 1);
+        reference.insert(1, 1);
+        assert_eq!(hs, reference);
+
+        let x = 4777;
+        let hs = get_amount_of_digits(&x);
+        let mut reference = get_new_map();
+        reference.insert(4, 1);
+        reference.insert(7, 3);
+        assert_eq!(hs, reference);
+    }
+
+    #[test]
+    fn test_satisfies_checks() {
+        let input: Solution = [1234, 3241, 4321];
+        assert!(satisfies_checks(&input));
+
+        let input: Solution = [1254, 3241, 4321];
+        assert!(!satisfies_checks(&input));
+    }
+}