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ProjectEulerRust/src/Problems/Problem35.rs

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2.9 KiB
Rust

//ProjectEulerRust/src/Problems/Problem35.rs
//Matthew Ellison
// Created: 06-06-21
//Modified: 06-06-21
//How many circular primes are there below one million?
//Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/RustClasses
/*
Copyright (C) 2021 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{
"How many circular primes are there below one million?".to_string()
}
pub fn solve() -> Answer{
//Variables
//Static variables
let maxNum = 999999; //The largest number that we are checking for primes
//Instance variables
let mut circularPrimes = Vec::<i64>::new();
//Start the timer
let mut timer = myClasses::Stopwatch::Stopwatch::new();
timer.start();
//Get all primes under 1,000,000
let primes = myClasses::Algorithms::getPrimes(maxNum);
//Go through all primes, get all their rotations, and check if those numbers are also primes
for num in &primes{
let prime = *num;
let mut allRotationsPrime = true;
//Get all of the rotations of the prime and see if they are also prime
let rotations = getRotations(&prime.to_string());
for rotation in rotations{
let p = rotation.parse::<i64>().unwrap();
if(!primes.contains(&p)){
allRotationsPrime = false;
break;
}
}
//If all rotations are prime add it to the list of circular primes
if(allRotationsPrime){
circularPrimes.push(prime);
}
}
//Stop the timer
timer.stop();
return Answer::new(format!("The number of all circular prime numbers under {} is {}", maxNum, circularPrimes.len()), timer.getString(), timer.getNano());
}
fn getRotations(par1: &String) -> Vec::<String>{
let mut string = String::from(par1);
let stringCount = String::from(par1).chars().count();
let mut rotations = Vec::<String>::new();
rotations.push(string.to_string());
for _cnt in 1 as usize .. stringCount{
let mut tempString = string[1..].to_string();
let tempString2 = string[..1].to_owned();
tempString.push_str(&tempString2);
string = String::from(tempString);
rotations.push(string.to_string());
}
return rotations;
}
/* Results:
The number of all circular prime numbers under 999999 is 55
It took an average of 3.576 seconds to run this problem through 100 iterations
*/