java-求100的阶乘-100！(即100*99*98*二*1)，不用BigInteger

java-求100的阶乘-100！(即100*99*98*...*2*1)，不用BigInteger
BigIntegerAddition.add见http://bylijinnan.iteye.com/blog/1463337

public class FactorialInAddition {/** *题目：求100的阶乘-100！(即100*99*98*...*2*1) *方法：用加法代替乘法，加法的加数用字符串表示 */public static void main(String[] args) {for(int i=1;i<=100;i++){System.out.println(factorial(i));}}//return n!public static String factorial(int n){if(n<=0){return null;}String result="1";String tmp="0";for(int i=2;i<=n;i++){for(int j=0;j<i;j++){//I write 'BigIntegerAddition' in my own BigIntegerAddition.javatmp=BigIntegerAddition.add(result, tmp);//String add(String,String)}result=tmp;tmp="0";}return result;}}