Created
February 12, 2012 20:49
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Emebdly R
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import java.math.BigDecimal; | |
public class R { | |
public static BigDecimal factorial(BigDecimal n) { | |
if (n.equals(BigDecimal.ONE)) { | |
return BigDecimal.ONE; | |
} | |
return n.multiply(factorial(n.subtract(BigDecimal.ONE))); | |
} | |
public static BigDecimal r(BigDecimal n) { | |
BigDecimal f = factorial(n); | |
BigDecimal r = new BigDecimal(0); | |
while(f.compareTo(BigDecimal.ZERO) > 0) { | |
BigDecimal digit = f.remainder(BigDecimal.TEN); | |
r = r.add(digit); | |
f = f.subtract(digit); | |
f = f.divide(BigDecimal.TEN); | |
} | |
System.out.println("R(" + n + ") = " + r); | |
return r; | |
} | |
/** | |
* @param args | |
*/ | |
public static void main(String[] args) { | |
System.out.println("R(10) = " + r(BigDecimal.TEN).toString()); | |
BigDecimal answer = new BigDecimal(8001); | |
BigDecimal n = new BigDecimal(4); | |
while (r(n).compareTo(answer) != 0) { | |
n = n.add(BigDecimal.ONE); | |
} | |
} | |
} |
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