From c5f395baf824c30131e0fc7c3bced9bea46a132e Mon Sep 17 00:00:00 2001 From: Mattrixwv Date: Tue, 16 Jun 2020 13:36:27 -0400 Subject: [PATCH] Added solution to Problem 14 --- src/Problems.rs | 1 + src/Problems/Problem14.rs | 90 +++++++++++++++++++++++++++++++++++++++ src/main.rs | 9 +++- 3 files changed, 99 insertions(+), 1 deletion(-) create mode 100644 src/Problems/Problem14.rs diff --git a/src/Problems.rs b/src/Problems.rs index abaf009..81f2812 100644 --- a/src/Problems.rs +++ b/src/Problems.rs @@ -36,3 +36,4 @@ pub mod Problem10; pub mod Problem11; pub mod Problem12; pub mod Problem13; +pub mod Problem14; diff --git a/src/Problems/Problem14.rs b/src/Problems/Problem14.rs new file mode 100644 index 0000000..36c3afa --- /dev/null +++ b/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 . +*/ + + +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 +*/ diff --git a/src/main.rs b/src/main.rs index 211a9ce..6c65af5 100644 --- a/src/main.rs +++ b/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: ");