hw-horrible factorial n!. __ Note the use of big data functions BigInteger

Java.math.BigInteger Series Tutorials (iv) Reasons for the birth of BigInteger

Why is there a BigInteger type in Java? Believe that many people have this question, in fact, the reason is very simple, it can express a larger range of values, far more than the maximum value of long represents a large majority. Within an integer type, long can represent the maximum value, as follows:

1234567

public class Test {public static void main(String[] args) {System. Out. println(Long. Max_value); }}

The result is: 9223372036854775807
Using BigInteger, you can represent a larger value, theoretically, as long as you have enough memory, as in the following example:

12345678910

public class Test {public static void main(String[] args) {BigInteger a= BigInteger. ValueOf(9223372036854775807L); BigInteger b= BigInteger. ValueOf(9223372036854775807L); BigInteger C=a. Add(b); System. Out. println(C. ToString()); }}

The result is: 18446744073709551614

Because BigInteger does not overload the "+", "-", "*", "/", "%" of these five operators, it is not possible to perform data operations directly, you need to call its corresponding method: Add,subtract,multiply,divide,remainder.

The Java version is:

 Packaget0816;ImportJAva.math.BigInteger;  Public Final classBign { Public StaticBigInteger Multiply (BigInteger m,intN) {BigInteger sn=NewBigInteger (integer.tostring (n)); BigInteger sqy= M.Multiply(SN);//Big Data is subtraction with add, subtract, multiply, divide,remainder.         returnsqy; }               Public StaticString CALCNN (intN) {if(n >= 0) {BigInteger one=NewBigInteger (integer.tostring (1));//Initialization of 1             for(intI=1;i <= n;i++) { One=Multiply(One,i);//call the above-mentioned form of the accrual function;                }            returnone.tostring (); }        Else   return NULL; }          Public Static voidMain (String arg[]) {//Main functionSystem.out.println (CALCNN (13)); It is directly loaded here;}}

Output: 6227020800

hw-horrible factorial n!. __ Note the use of big data functions BigInteger