Problem 25

/**
 *
 * @author Mat
 */
package problem.pkg25;

import java.math.BigInteger;

public class Problem25 {

    public static void main(String[] args) {
        // Start of the Fibonacci sequence
        BigInteger A = BigInteger.ONE;
        BigInteger B = BigInteger.ONE;

        // to make DIGITS contain 10^999 which is a number that has 100 digits
        final BigInteger DIGITS = new BigInteger("10").pow(999);


        // for debuging to make sure the number is the correct number of digits
        String s1 = DIGITS.toString();
        System.out.println("Number of digits in s1: " + s1.length());

        // loop starts at 2 as sequence has been set at both ones
        for(int i = 2;;){
            A = A.add(B);
            i++;
            if(A.compareTo(DIGITS) >= 0){
                System.out.println("i is: " + i );
                System.out.println("A is: " + A.toString() );
                break;
            }

            B = B.add(A);
            i++;
            if(B.compareTo(DIGITS) >= 0){
                String s2 = B.toString();
                System.out.println("i is: " + i + "\n" );
                System.out.println("B is: " + B.toString());
                break;
            }
        }
    }
}
/* output
 * Number of digits in s1: 1000
 * i is: 4782
 * B is: 1070066266382758936764980584457396885083683896632151665013235203375314
 * 5206046940406218891475824897926578046948881775919574843364666725699595129960
 * 3046126274809248218614406943305123477444275027378175308757939166619214925918
 * 6759553966422837148943113074699503439547001985432609723067290192870526447243
 * 7261177158218255484911205250132014786129659313817922355596574520395061375514
 * 6783754322911960212993404826070617539770684706820289548690266618543512452190
 * 0369480641357447470911707619766945691070098024393439617474103736912503231365
 * 5321647736970231677550515951735184605799549194109677783732296657965816465139
 * 0348815425631018422419025984608800011018625555024549393711365165703944762958
 * 4714548523425950428582425306083544435428212611008992863795048006894330309773
 */