UVa 324 - Factorial Frequencies

时间：2022-07-01 11:50:22

　　题目大意：给一个数n，统计n的阶乘中各个数字出现的次数。用java的大数做。

 import java.io.*;

 import java.util.*;

 import java.math.*;

 class Main

 {

     public static void main(String[] args)

     {

         Scanner sc = new Scanner(System.in);

         BigInteger[] fact = new BigInteger[370];

         fact[0] = BigInteger.valueOf(1);

         for (int i = 1; i <= 366; i++)

             fact[i] = fact[i-1].multiply(BigInteger.valueOf(i));

         int[] cnt = new int[10];

         int n;

         while (sc.hasNext())

         {

             n = sc.nextInt();

             if (n == 0)  break;

             BigInteger f = fact[n];

             for (int i = 0; i < 10; i++)  cnt[i] = 0;

             while (f.compareTo(BigInteger.ZERO) > 0)

             {

                 BigInteger r = f.mod(BigInteger.valueOf(10));

                 int idx = r.intValue();

                 cnt[idx]++;

                 f = f.divide(BigInteger.valueOf(10));

             }

             System.out.printf("%d! --\n", n);

             System.out.printf("   (0)%5d    (1)%5d    (2)%5d    (3)%5d    (4)%5d\n", cnt[0], cnt[1], cnt[2], cnt[3], cnt[4]);

             System.out.printf("   (5)%5d    (6)%5d    (7)%5d    (8)%5d    (9)%5d\n", cnt[5], cnt[6], cnt[7], cnt[8], cnt[9]);

         }

     }

 }

　　一直不习惯java的输出，今天才发现c风格的printf函数，哈哈~

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