Solve problems 8, 9 in rust

docs/index.rst

@@ -110,9 +110,9 @@ This project is divided into several Makefiles, connected by a root Makefile whi
 +-----------+------+------+------+------+------+
 |:prob:`7`  |  |d| |      |      |  |d| |  |d| |
 +-----------+------+------+------+------+------+
-|:prob:`8`  |  |d| |      |      |  |d| |      |
+|:prob:`8`  |  |d| |      |      |  |d| |  |d| |
 +-----------+------+------+------+------+------+
-|:prob:`9`  |  |d| |      |      |  |d| |      |
+|:prob:`9`  |  |d| |      |      |  |d| |  |d| |
 +-----------+------+------+------+------+------+
 |:prob:`10` |  |d| |      |      |  |d| |  |d| |
 +-----------+------+------+------+------+------+

docs/rust/p0008.rst

@@ -0,0 +1,13 @@
+Rust Implementation of Problem 8
+================================
+
+View source code `here on GitHub! <https://github.com/LivInTheLookingGlass/Euler/blob/master/rust/src/p0008.rs>`_
+
+Problem Solution
+----------------
+
+.. rust:fn:: p0008::p0008() -> u64
+
+.. literalinclude:: ../../rust/src/p0008.rs
+   :language: rust
+   :linenos:

docs/rust/p0009.rst

@@ -0,0 +1,13 @@
+Rust Implementation of Problem 9
+================================
+
+View source code `here on GitHub! <https://github.com/LivInTheLookingGlass/Euler/blob/master/rust/src/p0009.rs>`_
+
+Problem Solution
+----------------
+
+.. rust:fn:: p0009::p0009() -> u64
+
+.. literalinclude:: ../../rust/src/p0009.rs
+   :language: rust
+   :linenos:

rust/src/main.rs

@@ -9,22 +9,23 @@ use rstest::rstest;
 #[cfg(test)]
 use itertools::Itertools;
 
-seq!(N in 0001..=0007 {
+seq!(N in 0001..=0010 {
 mod p~N;
 });
-mod p0010;
 mod primes;
 
 type ProblemType = fn() -> u64;
 type ProblemRef<'a> = (&'a str, ProblemType, u64);
-const ANSWERS: [ProblemRef; 8] = [
+const ANSWERS: [ProblemRef; 10] = [
     ("p0001", p0001::p0001, 233168),
     ("p0002", p0002::p0002, 4613732),
     ("p0003", p0003::p0003, 6857),
     ("p0004", p0004::p0004, 906609),
     ("p0005", p0005::p0005, 232792560),
     ("p0006", p0006::p0006, 25164150),
     ("p0007", p0007::p0007, 104743),
+    ("p0008", p0008::p0008, 23514624000),
+    ("p0009", p0009::p0009, 31875000),
     ("p0010", p0010::p0010, 142913828922),
 ];
 
@@ -40,7 +41,7 @@ fn main() {
 }
 
 #[cfg(test)]
-seq!(N in 0..8 {
+seq!(N in 0..10 {
 #[rstest]
 #[timeout(Duration::new(60, 0))]
 #(

rust/src/p0008.rs

@@ -0,0 +1,73 @@
+/*
+Project Euler Problem 8
+
+In Python I did this with an iterator, but that is more cumbersome here,
+so I just did it with a loop that slices.
+
+Problem:
+
+The four adjacent digits in the 1000-digit number that have the greatest
+product are 9 × 9 × 8 × 9 = 5832.
+
+73167176531330624919225119674426574742355349194934
+96983520312774506326239578318016984801869478851843
+85861560789112949495459501737958331952853208805511
+12540698747158523863050715693290963295227443043557
+66896648950445244523161731856403098711121722383113
+62229893423380308135336276614282806444486645238749
+30358907296290491560440772390713810515859307960866
+70172427121883998797908792274921901699720888093776
+65727333001053367881220235421809751254540594752243
+52584907711670556013604839586446706324415722155397
+53697817977846174064955149290862569321978468622482
+83972241375657056057490261407972968652414535100474
+82166370484403199890008895243450658541227588666881
+16427171479924442928230863465674813919123162824586
+17866458359124566529476545682848912883142607690042
+24219022671055626321111109370544217506941658960408
+07198403850962455444362981230987879927244284909188
+84580156166097919133875499200524063689912560717606
+05886116467109405077541002256983155200055935729725
+71636269561882670428252483600823257530420752963450
+
+Find the thirteen adjacent digits in the 1000-digit number that have the
+greatest product. What is the value of this product?
+*/
+
+
+pub fn p0008() -> u64 {
+    let string = concat!(
+        "73167176531330624919225119674426574742355349194934",
+        "96983520312774506326239578318016984801869478851843",
+        "85861560789112949495459501737958331952853208805511",
+        "12540698747158523863050715693290963295227443043557",
+        "66896648950445244523161731856403098711121722383113",
+        "62229893423380308135336276614282806444486645238749",
+        "30358907296290491560440772390713810515859307960866",
+        "70172427121883998797908792274921901699720888093776",
+        "65727333001053367881220235421809751254540594752243",
+        "52584907711670556013604839586446706324415722155397",
+        "53697817977846174064955149290862569321978468622482",
+        "83972241375657056057490261407972968652414535100474",
+        "82166370484403199890008895243450658541227588666881",
+        "16427171479924442928230863465674813919123162824586",
+        "17866458359124566529476545682848912883142607690042",
+        "24219022671055626321111109370544217506941658960408",
+        "07198403850962455444362981230987879927244284909188",
+        "84580156166097919133875499200524063689912560717606",
+        "05886116467109405077541002256983155200055935729725",
+        "71636269561882670428252483600823257530420752963450"
+    );
+    let mut answer: u64 = 0;
+    for i in 0..(string.len() - 13) {
+        let slice = &string[i..(i + 13)];
+        let mut prod: u64 = 1;
+        for c in slice.bytes() {
+            prod *= (c - '0' as u8) as u64;
+        }
+        if prod > answer {
+            answer = prod;
+        }
+    }
+    return answer;
+}

rust/src/p0009.rs

@@ -0,0 +1,32 @@
+/*
+Project Euler Problem 9
+
+
+
+Problem:
+
+A Pythagorean triplet is a set of three natural numbers, a < b < c, for which,
+a**2 + b**2 = c**2
+
+For example, 3**2 + 4**2 = 9 + 16 = 25 = 5**2.
+
+There exists exactly one Pythagorean triplet for which a + b + c = 1000.
+Find the product abc.
+*/
+const MAX = 500;
+
+pub fn p0009() -> u64 {
+    for c in 3..MAX {
+        let c_square = c * c;
+        for b in 2..c {
+            let b_square = b * b;
+            for a in 1..b {
+                let a_square = a * a;
+                if a_square + b_square == c_square && a + b + c == 1000 {
+                    return a * b * c;
+                }
+            }
+        }
+    }
+    return 0;
+}