Added solution to Problem 14

src/Problems.rs

@@ -36,3 +36,4 @@ pub mod Problem10;
 pub mod Problem11;
 pub mod Problem12;
 pub mod Problem13;
+pub mod Problem14;

src/Problems/Problem14.rs

@@ -0,0 +1,90 @@
+//ProjectEulerRust/src/Problems/Problems14.rs
+//Matthew Ellison
+// Created: 06-16-20
+//Modified: 06-16-20
+//Work out the first ten digits of the sum of the following one-hundred 50-digit numbers
+/*
+The following iterative sequence is defined for the set of positive integers:
+n → n/2 (n is even)
+n → 3n + 1 (n is odd)
+Which starting number, under one million, produces the longest chain?
+*/
+//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{
+	"Which starting number, under one million, produces the longest chain using the itterative sequence?".to_string()
+}
+
+pub fn solve() -> Answer{
+	let MAX_NUM = 1_000_000_i64;
+	//This is the length of the longest chain
+	let mut maxLength = 0i64;
+	//This is the starting number of the longest chain
+	let mut maxNum = 0i64;
+
+	//Start the timer
+	let mut timer = myClasses::Stopwatch::Stopwatch::new();
+	timer.start();
+
+	//Loop through all numbers less than MAX_NUM and check them against the series
+	for currentNum in 1i64..MAX_NUM{
+		let currentLength = checkSeries(currentNum);
+		//If the current number has a longer series than the max then the current becomes the max
+		if(currentLength > maxLength){
+			maxLength = currentLength;
+			maxNum = currentNum;
+		}
+	}
+
+	//Stop the timer
+	timer.stop();
+
+	//Return the results
+	return Answer::new(format!("The number {} produced a chain of {} steps", maxNum, maxLength), timer.getString());
+}
+
+fn checkSeries(startNum: i64) -> i64{
+	let mut num = startNum;
+	//Start at 1 because you need to count the starting number
+	let mut length = 1i64;
+
+	//Follow the series, adding 1 for each step you take
+	while(num > 1){
+		if((num % 2) == 0){
+			num /= 2;
+		}
+		else{
+			num = (3 * num) + 1;
+		}
+		length += 1;
+	}
+
+	//Return the length of the series
+	return length;
+}
+
+/* Results:
+The number 837799 produced a chain of 525 steps
+It took 98.253 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; 14] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13];
+static problemNumbers: [u32; 15] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14];
 
 fn main(){
 	let mut selection = Selections::EMPTY;
@@ -182,6 +182,10 @@ fn solveProblem(problemNumber: u32){
 		println!("{}", Problems::Problem13::getDescription());
 		println!("{}", Problems::Problem13::solve());
 	}
+	else if(problemNumber == 14){
+		println!("{}", Problems::Problem14::getDescription());
+		println!("{}", Problems::Problem14::solve());
+	}
 }
 fn descriptionMenu(){
 	//Give some extra space to print the description
@@ -246,6 +250,9 @@ fn printDescription(problemNumber: u32){
 	else if(problemNumber == 13){
 		println!("{}", Problems::Problem13::getDescription());
 	}
+	else if(problemNumber == 14){
+		println!("{}", Problems::Problem14::getDescription());
+	}
 }
 fn getProblemNumber() -> u32{
 	println!("Enter a problem number: ");