蓝桥杯练习题阶乘计算

[DemoRosie]

蓝桥杯练习题阶乘计算

不知道有什么问题，感觉思路是没有错的，求解答

package Basic_VIP;

import java.util.ArrayList;
import java.util.Scanner;
public class Basic_30 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        ArrayList<Integer> alist = new ArrayList<>();
        alist.add(1);
        for (int i=1;i<=n;i++){
            int size = alist.size();
            for (int j=0;j<size;j++){
//                先把每一位乘以i，再进行进位
                int temp = alist.get(j);
                temp *= i;
                alist.set(j,temp);
            }
            for (int m=0;m<size;m++){
                int temp1 = alist.get(m);
                if (temp1 > 10){
                    alist.set(m,temp1%10);
                    int tempResult = temp1/10;
                    if (size <= m+1){
                        alist.add(tempResult);
                    }else{
                        int temp2 = alist.get(m+1);
                        alist.set(m+1,temp2+tempResult);
                    }
                }else{
                    alist.set(m,temp1);
                }
            }
        }
        for (int i=alist.size()-1;i>-1;i--){
            System.out.print(alist.get(i));
        }
    }
}