Package net.n1da.dev.euler

Class PE0037

java.lang.Object

net.n1da.dev.euler.core.Problem

net.n1da.dev.euler.PE0037

All Implemented Interfaces:

Solvable

public class PE0037
extends Problem

Solution for problem 37 "Truncatable primes" completed on Mon, 14 Mar 2016, 20:06.

Since:

12.03.2016 07:38:47

Author:

Nico Danneberg

See Also:

Problem @ Project Euler, Solution @ Ni-Da-Net

Field Summary

Fields

Modifier and Type	Field	Description
private java.util.ArrayList<java.lang.Integer>	candidates	List of all primes less that 1,000,000.

Fields inherited from class net.n1da.dev.euler.core.Problem

number, title

Constructor Summary

Constructors

Constructor	Description
PE0037()	A simple constructor to set number and title.

Method Summary

Modifier and Type	Method	Description
void	prepare()	Just initializes the attributes and stores all primes less than 1,000,000 in candidates if the do not start with 4, 6, or 8, and do not end with 0, 2, 4, 6, or 8.
java.lang.String	solve()	Every candidate is proved by method test(int).
private boolean	test(int num)	Truncates the given number from both sides and tests if the both new numbers are primes (are stored in candidates).

Methods inherited from class net.n1da.dev.euler.core.Problem

finish, getResult, getRuntime, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

candidates

private java.util.ArrayList<java.lang.Integer> candidates

List of all primes less that 1,000,000.

Constructor Detail

PE0037

public PE0037()

A simple constructor to set number and title.

Method Detail

prepare

public void prepare()

Just initializes the attributes and stores all primes less than 1,000,000 in candidates if the do not start with 4, 6, or 8, and do not end with 0, 2, 4, 6, or 8.

Specified by:

prepare in interface Solvable

Overrides:

prepare in class Problem

See Also:

Sieve

solve

public java.lang.String solve()

Every candidate is proved by method test(int). If it returns true and the number is greater zero it is summed to the searched result.

Returns:

the sum of all primes that are tested true

test

private boolean test(int num)

Truncates the given number from both sides and tests if the both new numbers are primes (are stored in candidates).

Parameters:

num - the number to be tested

Returns:

true if, and only if the number can be truncated from left and right and all resulting numbers are primes