SquareDigits的算法简单实现,SquareDigits是topcoder的一个问题-

Problem Statement

       

***Note:　Please keep programs under 7000 characters in length.　Thank you





Class Name: SquareDigits

Method Name: smallestResult

Parameters: int

Returns: int



Define the function S(x) as the sum of the squares of the digits of x.　

For example: S(3)=3*3=9 and S(230)=2*2+3*3+0*0=13.



Define the set T(x) to be the set of unique numbers that are produced by

repeatedly applying S to x.　That is: S(x), S(S(x)), S(S(S(x))), etc...

For example, repeatedly applying S to 37:

S(37)=3*3+7*7=58.　

S(58)=5*5+8*8=89.

S(89)=145.

S(145)=42.

S(42)=20.

S(20)=4.

S(4)=16.

S(16)=37.

Note this sequence will repeat so we can stop calculating now and:

T(37)={58,89,145,42,20,4,16,37}.

However, note T(x) may not necessarily contain x.　



Implement a class SquareDigits, which contains a method smallestResult.　The

method takes an int, n, as a parameter and returns the smallest int, x, such

that T(x) contains n.



The method signatu