设计一个可容纳40位数(int)的求n!的程序
*/
public class Factorial40th
{
public static void main(String[] args)
{
final int numBits = 28;
int[] arrBits = new int[40];
int digit = 1;//数据位数
arrBits[0] = arrBits[1] = 1;
for(int i=1; i<numBits+1; i++)
{
for(int j=1; j<digit+1; j++)
{
arrBits[j] *= i;
}
for(int j=1; j<digit+1; j++)
{
if(arrBits[j] > 10)
{
for(int r=1; r<digit+1; r++)
{
if(arrBits[digit] > 10)
{
digit++;
}
arrBits[r+1] += arrBits[r]/10;
arrBits[r] = arrBits[r]%10;
}
}
}
System.out.print(i + "! = ");
for(int k=digit; k>0; k--)
{
System.out.print(arrBits[k]);
}
System.out.println();
}
}
}
1! = 1
2! = 2
3! = 6
4! = 24
5! = 120
6! = 720
7! = 5040
8! = 40320
9! = 362880
10! = 3628800
11! = 39916800
12! = 479001600
13! = 6227020800
14! = 87178291200
15! = 1307674368000
16! = 20922789888000
17! = 355687428096000
18! = 6402373705728000
19! = 121645100408832000
20! = 2432902008176640000
21! = 51090942171709440000
22! = 1124000727777607680000
23! = 25852016738884976640000
24! = 620448401733239439360000
25! = 15511210043330985984000000
26! = 403291461126605635584000000
27! = 0888869450418352160768000000
28! = 34888344611713860501504000000//right:304888344611713860501504000000
28!计算结果是错的！为何？
