UVa 10519 - !! Really Strange !!

题意

思路

代码

import java.math.*;
import java.io.*;
import java.util.*;

public class Main {

static public void main(String[] args) {
Scanner in = new Scanner(System.in);
while (in.hasNext()) {
BigInteger n = in.nextBigInteger();
if (n.compareTo(BigInteger.ZERO) == 0) {
System.out.println("1");
continue;
}
n = n.multiply(n.subtract(BigInteger.ONE)).add(BigInteger.valueOf(2));
System.out.println(n);
}
}
}