add main loop for 51 (WIP)

euler51/src/main.rs

@@ -4,11 +4,66 @@ use crate::primes::Primes;
 
 type Int = i64;
 
-const MIN_VALUE: Int = 10_000_000;
-const MAX_VALUE: Int = 10_010_000;
+const MIN_VALUE: Int = 10_000;
+const MAX_VALUE: Int = 99_999;
+
+const DIGITS: [Int; 10] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+// const MIN_VALUE: Int = 10_000_000;
+// const MAX_VALUE: Int = 10_010_000;
 // const MAX_VALUE: Int = 99_999_999;
 
 fn main() {
     let primes = Primes::get_between(MIN_VALUE, MAX_VALUE);
     println!("{}", primes.vector[0]);
+    for p in primes.vector {
+        let mut candidates = vec![];
+        let digits = num_to_digits(p);
+        for d in DIGITS {
+            let mut these_digits = digits.clone();
+            these_digits[3] = d;
+            these_digits[4] = d;
+            let num = digits_to_num(these_digits);
+            if primes.set.contains(&num) {
+                candidates.push(num)
+            }
+        }
+        println!("candidates");
+        for c in candidates {
+            println!("{c}");
+        }
+    }
+}
+
+fn num_to_digits(n: Int) -> Vec<Int> {
+    n.to_string()
+        .chars()
+        .map(|x| x.to_digit(10).unwrap() as Int)
+        .collect()
+}
+
+fn digits_to_num(vec: Vec<Int>) -> Int {
+    let mut result = 0;
+    let mut position = 1;
+    for digit in vec.iter().rev() {
+        result += digit * position;
+        position *= 10;
+    }
+    result
+}
+
+#[cfg(test)]
+mod test {
+    use crate::{digits_to_num, num_to_digits};
+
+    #[test]
+    fn test_digits_to_num() {
+        let digits = vec![5, 7, 3, 8, 1];
+        assert_eq!(digits_to_num(digits), 57381);
+    }
+
+    #[test]
+    fn test_num_to_digits() {
+        let num = 83371;
+        assert_eq!(num_to_digits(num), vec![8, 3, 3, 7, 1]);
+    }
 }

euler51/src/primes.rs

@@ -27,8 +27,9 @@ impl<T: Num + ToPrimitive + FromPrimitive + Hash + Eq + PartialEq + Copy> Primes
         let mut set = HashSet::new();
         for number in *min_value..*max_value {
             if array[(number - min_value) as usize] {
-                vector.push(FromPrimitive::from_usize(number).unwrap());
-                set.insert(FromPrimitive::from_usize(number).unwrap());
+                let prime = FromPrimitive::from_usize(number).unwrap();
+                vector.push(prime);
+                set.insert(prime);
             }
         }
         Primes { vector, set }
@@ -56,4 +57,9 @@ impl<T: Num + ToPrimitive + FromPrimitive + Hash + Eq + PartialEq + Copy> Primes
         }
         result
     }
+
+    pub fn remove(&mut self, num: T) {
+        let index = self.vector.iter().position(|x| x == &num).unwrap();
+        self.vector.remove(index);
+    }
 }