Added solution to problem 8

src/Problems.rs

@@ -30,3 +30,4 @@ pub mod Problem4;
 pub mod Problem5;
 pub mod Problem6;
 pub mod Problem7;
+pub mod Problem8;

src/Problems/Problem8.rs

@@ -0,0 +1,86 @@
+//ProjectEulerRust/src/Problems/Problems8.rs
+//Matthew Ellison
+// Created: 06-15-20
+//Modified: 06-15-20
+//Find the thirteen adjacent digits in the 1000-digit number that have the greatest product. What is the value of this product?
+/*
+73167176531330624919225119674426574742355349194934
+96983520312774506326239578318016984801869478851843
+85861560789112949495459501737958331952853208805511
+12540698747158523863050715693290963295227443043557
+66896648950445244523161731856403098711121722383113
+62229893423380308135336276614282806444486645238749
+30358907296290491560440772390713810515859307960866
+70172427121883998797908792274921901699720888093776
+65727333001053367881220235421809751254540594752243
+52584907711670556013604839586446706324415722155397
+53697817977846174064955149290862569321978468622482
+83972241375657056057490261407972968652414535100474
+82166370484403199890008895243450658541227588666881
+16427171479924442928230863465674813919123162824586
+17866458359124566529476545682848912883142607690042
+24219022671055626321111109370544217506941658960408
+07198403850962455444362981230987879927244284909188
+84580156166097919133875499200524063689912560717606
+05886116467109405077541002256983155200055935729725
+71636269561882670428252483600823257530420752963450
+*/
+//Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/RustClasses
+/*
+	Copyright (C) 2020  Matthew Ellison
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU Lesser General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU Lesser General Public License for more details.
+
+	You should have received a copy of the GNU Lesser General Public License
+	along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+
+extern crate myClasses;
+use crate::Problems::Answer::Answer;
+
+
+pub fn getDescription() -> String{
+	"What is the 10001th prime number?".to_string()
+}
+
+pub fn solve() -> Answer{
+	//Setup the variables
+	let NUMBER = "7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450";
+	let mut maxNums = "".to_string();
+	let mut maxProduct = 0u64;	//u64 because 2^32 < 9^13
+
+	//Start the timer
+	let mut timer = myClasses::Stopwatch::Stopwatch::new();
+	timer.start();
+
+	//Cycle through the string of number looking for the maximum product
+	for cnt in 12..NUMBER.len(){
+		let currentProduct = NUMBER.chars().nth(cnt - 12).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 11).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 10).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 9).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 8).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 7).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 6).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 5).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 4).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 3).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 2).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt - 1).unwrap().to_digit(10).unwrap() as u64 * NUMBER.chars().nth(cnt).unwrap().to_digit(10).unwrap() as u64;
+		//Check if the product is greater than the current maximum
+		if(currentProduct > maxProduct){
+			maxNums = NUMBER.chars().skip(cnt - 12).take(13).collect();
+			maxProduct = currentProduct;
+		}
+	}
+
+	//Start the timer
+	timer.stop();
+
+	//Return the results
+	return Answer::new(format!("The greatest product is {}\nThe numbers are {}", maxProduct, maxNums), timer.getString());
+}
+
+/* Results:
+The greatest product is 23514624000
+The numbers are 5576689664895
+It took 2.778 milliseconds to solve this problem
+*/

src/main.rs

@@ -33,7 +33,7 @@ mod Problems;
 #[derive(PartialEq)]
 enum Selections{EMPTY, SOLVE, DESCRIPTION, LIST, EXIT, SIZE}
 
-static problemNumbers: [u32; 8] = [0, 1, 2, 3, 4, 5, 6, 7];
+static problemNumbers: [u32; 9] = [0, 1, 2, 3, 4, 5, 6, 7, 8];
 
 fn main(){
 	let mut selection = Selections::EMPTY;
@@ -158,6 +158,10 @@ fn solveProblem(problemNumber: u32){
 		println!("{}", Problems::Problem7::getDescription());
 		println!("{}", Problems::Problem7::solve());
 	}
+	else if(problemNumber == 8){
+		println!("{}", Problems::Problem8::getDescription());
+		println!("{}", Problems::Problem8::solve());
+	}
 }
 fn descriptionMenu(){
 	//Give some extra space to print the description
@@ -204,6 +208,9 @@ fn printDescription(problemNumber: u32){
 	else if(problemNumber == 7){
 		println!("{}", Problems::Problem7::getDescription());
 	}
+	else if(problemNumber == 8){
+		println!("{}", Problems::Problem8::getDescription());
+	}
 }
 fn getProblemNumber() -> u32{
 	println!("Enter a problem number: ");