From f600938944f97879d71761de3f85d510c876cc4a Mon Sep 17 00:00:00 2001
From: Mattrixwv <m_ellison@ymail.com>
Date: Tue, 16 Jun 2020 19:22:05 -0400
Subject: [PATCH] Added solution to problem 16

---
 src/Problems.rs           |  1 +
 src/Problems/Problem16.rs | 66 +++++++++++++++++++++++++++++++++++++++
 src/main.rs               | 11 +++++--
 3 files changed, 76 insertions(+), 2 deletions(-)
 create mode 100644 src/Problems/Problem16.rs

diff --git a/src/Problems.rs b/src/Problems.rs
index e408959..e0ae5c6 100644
--- a/src/Problems.rs
+++ b/src/Problems.rs
@@ -38,3 +38,4 @@ pub mod Problem12;
 pub mod Problem13;
 pub mod Problem14;
 pub mod Problem15;
+pub mod Problem16;
diff --git a/src/Problems/Problem16.rs b/src/Problems/Problem16.rs
new file mode 100644
index 0000000..3129c88
--- /dev/null
+++ b/src/Problems/Problem16.rs
@@ -0,0 +1,66 @@
+//ProjectEulerRust/src/Problems/Problems16.rs
+//Matthew Ellison
+// Created: 06-16-20
+//Modified: 06-16-20
+//What is the sum of the digits of the number 2^1000?
+//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{
+	//The number that is going to be raised to a power
+	let NUM_TO_POWER = 2;
+	//The pwer that the number is going to be raised to
+	let POWER = 1000;
+	//The number to be calculated
+	let mut sumOfElements = 0u64;
+
+	//Start the timer
+	let mut timer = myClasses::Stopwatch::Stopwatch::new();
+	timer.start();
+
+	//Get the number
+	let number = num::pow::pow(num::BigInt::from(NUM_TO_POWER), POWER);
+
+	//Get a string of the number
+	let numString = number.to_str_radix(10);
+
+	//Add up the individual characters of the string
+	for n in numString.chars(){
+		sumOfElements += n.to_digit(10).unwrap() as u64;
+	}
+
+	//Stop the timer
+	timer.stop();
+
+	//Return the results
+	return Answer::new(format!("{}^{} = {}\nThe sum of the elements is {}", NUM_TO_POWER, POWER, number, sumOfElements), timer.getString());
+}
+
+/* Results:
+2^1000 = 10715086071862673209484250490600018105614048117055336074437503883703510511249361224931983788156958581275946729175531468251871452856923140435984577574698574803934567774824230985421074605062371141877954182153046474983581941267398767559165543946077062914571196477686542167660429831652624386837205668069376
+The sum of the elements is 1366
+It took 8.200 microseconds to solve this problem
+*/
diff --git a/src/main.rs b/src/main.rs
index 1886754..adf52b2 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -33,8 +33,8 @@ mod Problems;
 #[derive(PartialEq)]
 enum Selections{EMPTY, SOLVE, DESCRIPTION, LIST, EXIT, SIZE}
 
-static problemNumbers: [u32; 16] = [ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,
-									10, 11, 12, 13, 14, 15];
+static problemNumbers: [u32; 17] = [ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,
+									10, 11, 12, 13, 14, 15, 16];
 
 fn main(){
 	let mut selection = Selections::EMPTY;
@@ -191,6 +191,10 @@ fn solveProblem(problemNumber: u32){
 		println!("{}", Problems::Problem15::getDescription());
 		println!("{}", Problems::Problem15::solve());
 	}
+	else if(problemNumber == 16){
+		println!("{}", Problems::Problem16::getDescription());
+		println!("{}", Problems::Problem16::solve());
+	}
 }
 fn descriptionMenu(){
 	//Give some extra space to print the description
@@ -261,6 +265,9 @@ fn printDescription(problemNumber: u32){
 	else if(problemNumber == 15){
 		println!("{}", Problems::Problem15::getDescription());
 	}
+	else if(problemNumber == 16){
+		println!("{}", Problems::Problem16::getDescription());
+	}
 }
 fn getProblemNumber() -> u32{
 	println!("Enter a problem number: ");