diff --git a/src/Problems.rs b/src/Problems.rs index 164152b..058470e 100644 --- a/src/Problems.rs +++ b/src/Problems.rs @@ -48,3 +48,4 @@ pub mod Problem22; pub mod Problem23; pub mod Problem24; pub mod Problem25; +pub mod Problem26; diff --git a/src/Problems/Problem26.rs b/src/Problems/Problem26.rs new file mode 100644 index 0000000..51e4ed0 --- /dev/null +++ b/src/Problems/Problem26.rs @@ -0,0 +1,92 @@ +//ProjectEulerRust/src/Problems/Problems26.rs +//Matthew Ellison +// Created: 06-17-20 +//Modified: 06-17-20 +//Find the value of d < 1000 for which 1/d contains the longest recurring cycle in its decimal fraction part. +//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{ + "Find the value of d < 1000 for which 1/d contains the longest recurring cycle in its decimal fraction part.".to_string() +} + +pub fn solve() -> Answer{ + let TOP_NUM = 999; + //The length of the longest cycle + let mut longestCycle = 0; + //The starting denominator of the longest cycle + let mut longestNumber = 0; + + //Start the timer + let mut timer = myClasses::Stopwatch::Stopwatch::new(); + timer.start(); + + //Start with 1/2 and find out how long the longest cycle is by checking the remainders + //Loop through every number from 2-999 and use it for the denominator + for denominator in 2..=TOP_NUM{ + let mut denomList = Vec::::new(); + let mut endFound = false; //Whether we have found an end to the number (either a cycle or a 0 for remainder) + let mut cycleFound = false; //Whether a cycle was detected + let mut numerator = 1; //The numerator that will be divided. Always starts at 1 + while(!endFound){ + //Get the remainder after the division + let remainder = numerator % denominator; + //Check if the remainder is 0 + //If it is set the flag + if(remainder == 0){ + endFound = true; + } + //Check if the remainder is in the list + //If it is in the list, set the appropriate flags + else if(denomList.contains(&remainder)){ + endFound = true; + cycleFound = true; + } + //Else add it to the list + else{ + denomList.push(remainder); + } + //Multiply the remainder by 10 to continue finding the next remainder + numerator = remainder * 10; + } + //If a cycle was found check the size of the list against the largest cycle + if(cycleFound){ + //If it is larger than the largest, set it as the new largest + if(denomList.len() > longestCycle){ + longestCycle = denomList.len(); + longestNumber = denominator; + } + } + } + + //Stop the timer + timer.stop(); + + //Return the results + return Answer::new(format!("The longest cycle is {} digits long\nIt started with the number {}", longestCycle, longestNumber), timer.getString()); +} + +/* Results: +The longest cycle is 982 digits long +It started with the number 983 +It took 6.518 milliseconds to solve this problem +*/ diff --git a/src/main.rs b/src/main.rs index 8ce278d..478a2c2 100644 --- a/src/main.rs +++ b/src/main.rs @@ -33,9 +33,9 @@ mod Problems; #[derive(PartialEq)] enum Selections{EMPTY, SOLVE, DESCRIPTION, LIST, EXIT, SIZE} -static problemNumbers: [u32; 26] = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, +static problemNumbers: [u32; 27] = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, - 20, 21, 22, 23, 24, 25]; + 20, 21, 22, 23, 24, 25, 26]; fn main(){ let mut selection = Selections::EMPTY; @@ -232,6 +232,10 @@ fn solveProblem(problemNumber: u32){ println!("{}", Problems::Problem25::getDescription()); println!("{}", Problems::Problem25::solve()); } + else if(problemNumber == 26){ + println!("{}", Problems::Problem26::getDescription()); + println!("{}", Problems::Problem26::solve()); + } } fn descriptionMenu(){ //Give some extra space to print the description @@ -332,6 +336,9 @@ fn printDescription(problemNumber: u32){ else if(problemNumber == 25){ println!("{}", Problems::Problem25::getDescription()); } + else if(problemNumber == 26){ + println!("{}", Problems::Problem26::getDescription()); + } } fn getProblemNumber() -> u32{ println!("Enter a problem number: ");