Data update

Task/Sylvesters-sequence/Java/sylvesters-sequence.java

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+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.math.MathContext;
+import java.math.RoundingMode;
+
+public final class SylvestersSequence {
+
+	public static void main(String[] args) {
+		System.out.println("The first 10 terms in Sylvester's sequence are:");
+		BigInteger term = BigInteger.TWO;
+		BigRational sum = BigRational.ZERO;
+	    for ( int i = 1; i <= 10; i++ ) {
+	    	System.out.println(term);
+	        sum = sum.add( new BigRational(BigInteger.ONE, term) );
+	        term = term.multiply(term).subtract(term).add(BigInteger.ONE);
+	    }
+	    System.out.println();
+	
+	    System.out.println("The sum of their reciprocals as a rational number is:");
+	    System.out.println(sum + System.lineSeparator());	
+	
+	    System.out.println("The sum of their reciprocals as a decimal number, to 235 decimal places, is:");
+	    System.out.println(sum.toDecimal(235));
+	}
+
+}
+
+final class BigRational {
+	
+	public BigRational(BigInteger aNumerator, BigInteger aDenominator) {
+		numerator = aNumerator;
+		denominator = aDenominator;
+		
+    	BigInteger gcd = numerator.gcd(denominator);	    	
+    	numerator = numerator.divide(gcd);
+    	denominator = denominator.divide(gcd);
+    }
+	
+	public BigRational add(BigRational other) {
+		BigInteger numer = numerator.multiply(other.denominator).add(denominator.multiply(other.numerator));
+		BigInteger denom = denominator.multiply(other.denominator);		
+		return new BigRational(numer, denom);
+	}	
+	
+	public String toDecimal(int decimalPlaces) {
+		BigDecimal numer = new BigDecimal(numerator);
+		BigDecimal denom = new BigDecimal(denominator);
+		return numer.divide(denom, new MathContext(decimalPlaces + 1, RoundingMode.HALF_UP)).toString();
+	}	
+	
+	public String toString() {
+		return numerator.toString() + " / " + denominator.toString();
+	}
+
+	public static final BigRational ZERO = new BigRational(BigInteger.ZERO, BigInteger.ONE);
+	
+	private BigInteger numerator;
+	private BigInteger denominator;
+	
+}