66 lines
1.8 KiB
Java
66 lines
1.8 KiB
Java
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/*
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This is a Java Program to Implement Fermat Factorization Algorithm. Fermat’s factorization method, named after Pierre de Fermat, is based on the representation of an odd integer as the difference of two squares: N = a2 – b2. That difference is algebraically factorable as (a + b)(a – b); if neither factor equals one, it is a proper factorization of N.
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*/
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/**
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** Java Program to implement Fermat Factorization Algorithm
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**/
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import java.util.Scanner;
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public class FermatFactorization
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{
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/** Fermat factor **/
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public void FermatFactor(long N)
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{
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long a = (long) Math.ceil(Math.sqrt(N));
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long b2 = a * a - N;
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while (!isSquare(b2))
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{
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a++;
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b2 = a * a - N;
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}
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long r1 = a - (long)Math.sqrt(b2);
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long r2 = N / r1;
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display(r1, r2);
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}
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/** function to display roots **/
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public void display(long r1, long r2)
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{
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System.out.println("\nRoots = "+ r1 +" , "+ r2);
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}
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/** function to check if N is a perfect square or not **/
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public boolean isSquare(long N)
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{
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long sqr = (long) Math.sqrt(N);
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if (sqr * sqr == N || (sqr + 1) * (sqr + 1) == N)
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return true;
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return false;
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}
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/** main method **/
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public static void main(String[] args)
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{
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Scanner scan = new Scanner(System.in);
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System.out.println("Fermat Factorization Test\n");
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System.out.println("Enter odd number");
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long N = scan.nextLong();
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FermatFactorization ff = new FermatFactorization();
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ff.FermatFactor(N);
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}
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}
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/*
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Enter odd number
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5959
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Roots = 59 , 101
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Fermat Factorization Test
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Enter odd number
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432633
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Roots = 499 , 867
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