Whats wrong with it. All results are correct and i think i transformed the double correct to a String, didnt't I?
package de.codegym.task.task15.task1531;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigDecimal;
/*
Fakultät
*/
public class Solution {
public static void main(String[] args) throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
int input = Integer.parseInt(reader.readLine());
reader.close();
System.out.println(factorial(input));
}
public static String factorial(int n) {
double fakultaet = 1;
double i = n;
String k = "0";
if(n<0){
return k;
}else if(n == 0){
k = String.valueOf(1);
}
else{
while ( i > 1 )
{
fakultaet = fakultaet * i;
i = i - 1;
}
k = String.valueOf(fakultaet);
return k;}
return k;}
}