ACMICPC

加法： import java.math.BigInteger; import java.util.*; public class Main { public static void main(String args[]) { Scanner scan = new Scanner(System.in); BigInteger a = scan.nextBigInteger();

1^2+2^2+3^2+......+n^2 =n(n+1)(2n+1)/6 1^2+3^2+5^2+......+n^2=n(n+1)(n+2)/6