http://e-tutor.itsa.org.tw/e-Tutor/mod/programming/view.php?id=30526
這題要注意可能會溢位必須要用BigInteger,有大小寫區分 ex: 排列組合abbccc =>6!/(1!2!3!)
package ITSA;
import java.math.BigInteger;
import java.util.*;
public class Test {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int test=Integer.parseInt(sc.nextLine());
for(int j=0;j<test;++j)
{
String in=sc.nextLine();
String[] split=in.split(" ");
char[] arr=split[1].toCharArray();
int[] count=new int[52];
BigInteger bi=new BigInteger("1");
for(int i=1;i<=arr.length;++i)
{
bi=bi.multiply(new BigInteger(Integer.toString(i)));
if(arr[i-1]>='a' && arr[i-1]<='z')
count[arr[i-1]-'a']++;
if(arr[i-1]>='A' && arr[i-1]<='Z')
count[arr[i-1]-'A'+26]++;
}
for(int i=0;i<count.length;++i)
{
if(count[i]>1)
{
for(int k=count[i];k>0;--k)
bi=bi.divide(new BigInteger(Integer.toString(k)));
}
}
System.out.println(bi.mod(new BigInteger(split[0])));
}
}
/*
題目:2016 闖關組 [Problem B10] Password Complexity
作者:1010
時間:西元 2016 年 8 月 */
}