RosettaCodeData/Task/Factorial/Java/factorial-3.java

38 lines
1.4 KiB
Java

import java.math.BigInteger;
import java.util.InputMismatchException;
import java.util.Scanner;
public class LargeFactorial {
public static long userInput;
public static void main(String[]args){
Scanner input = new Scanner(System.in);
System.out.println("Input factorial integer base: ");
try {
userInput = input.nextLong();
System.out.println(userInput + "! is\n" + factorial(userInput) + " using standard factorial method.");
System.out.println(userInput + "! is\n" + factorialRec(userInput) + " using recursion method.");
}catch(InputMismatchException x){
System.out.println("Please give integral numbers.");
}catch(StackOverflowError ex){
if(userInput > 0) {
System.out.println("Number too big.");
}else{
System.out.println("Please give non-negative(positive) numbers.");
}
}finally {
System.exit(0);
}
}
public static BigInteger factorialRec(long n){
BigInteger result = BigInteger.ONE;
return n == 0 ? result : result.multiply(BigInteger.valueOf(n)).multiply(factorial(n-1));
}
public static BigInteger factorial(long n){
BigInteger result = BigInteger.ONE;
for(int i = 1; i <= n; i++){
result = result.multiply(BigInteger.valueOf(i));
}
return result;
}
}