problem 1 2 3 in rust

3 files changed, 98 insertions, 0 deletions

diff --git a/rust/001-multiples_of_3_and_5.rs b/rust/001-multiples_of_3_and_5.rs
new file mode 100644
index 0000000..ac30587
--- /dev/null
+++ b/rust/001-multiples_of_3_and_5.rs
@@ -0,0 +1,18 @@
+/*
+* Multiples of 3 and 5
+* Problem 1
+*
+* If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.
+* Find the sum of all the multiples of 3 or 5 below 1000.
+*/
+
+fn main() {
+    let mut sum = 0;
+
+    for x in 1..999 {
+        if x % 3 == 0 || x % 5 == 0 {
+            sum += x;
+        }
+    }
+    println!("{}", sum);
+}
diff --git a/rust/002-even_fibonacci_numbers.rs b/rust/002-even_fibonacci_numbers.rs
new file mode 100644
index 0000000..1f95f3a
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+++ b/rust/002-even_fibonacci_numbers.rs
@@ -0,0 +1,41 @@
+/*
+* Even Fibonacci numbers
+* Problem 2
+*
+* Each new term in the Fibonacci sequence is generated by adding the previous two terms.
+* By starting with 1 and 2, the first 10 terms will be:
+* 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
+* By considering the terms in the Fibonacci sequence whose values do not exceed four million,
+* find the sum of the even-valued terms.
+*/
+
+struct Fib {
+    a: u32,
+    b: u32
+}
+
+impl Iterator for Fib {
+    type Item = u32;
+
+    fn next(&mut self) -> Option<u32> {
+        let c = self.a + self.b;
+        self.a = self.b;
+        self.b = c;
+        return Some(c)
+    }
+}
+
+fn main() {
+    let fib = Fib { a: 0, b: 1 };
+    let mut sum = 0;
+
+    for f in fib {
+        if f > 4_000_000 {
+            break;
+        }
+        if f % 2 == 0 {
+            sum += f;
+        }
+    }
+    println!("{}", sum);
+}
diff --git a/rust/003-largest_prime_factor.rs b/rust/003-largest_prime_factor.rs
new file mode 100644
index 0000000..2b84df1
--- /dev/null
+++ b/rust/003-largest_prime_factor.rs
@@ -0,0 +1,39 @@
+/*
+* Largest prime factor
+* Problem 3
+*
+* The prime factors of 13195 are 5, 7, 13 and 29.
+* What is the largest prime factor of the number 600851475143 ?
+*/
+
+// fn is_prime(n: u64) -> bool {
+//     if n == 2 || n == 3 || n == 5 || n == 7 {
+//         return true;
+//     }
+//     if n % 2 == 0 || n % 3 == 0 {
+//         return false;
+//     }
+//
+//     for i in (6..n).step_by(6) {
+//         if n % (i - 1) == 0 || n % (i + 1) == 0 {
+//             return true;
+//         }
+//     }
+//     return false;
+// }
+
+fn main() {
+    let mut target: u64 = 600851475143;
+    let mut n: u64 = 2;
+    let mut last = 0;
+
+    while target > 1 {
+        if target % n == 0  {
+            last = n;
+            target /= n;
+            n = 2;
+        }
+        n += 1;
+    }
+    println!("{}", last);
+}