java - 凯撒密码(频率列表)

Question

我正在处理凯撒密码问题，到目前为止我的所有测试用例都有效，但是在处理频率列表时出现了我的问题。任何帮助将不胜感激!

    public class CaesarCipher 
    {
    //Percentage frequencies for alphabet
    static double[] table = {8.2, 1.5, 2.8, 4.3, 12.7, 2.2, 2.0, 6.1, 7.0, 0.2, 0.8, 4.0, 2.4, 6.7,
                7.5, 1.9, 0.1, 6.0, 6.3, 9.1, 2.8, 1.0, 2.4, 0.2, 2.0, 0.1};

    //convert letter to number
    static int let2nat(char c)
    {
        return ((int) c) - 97;
    }

    //convert number to letter
    static char nat2let(int code)
    {
        return (char) (code + 97);
    }

    //shift a letter to another letter
    static char shift(int shftAmt, char c)
    {
        if (let2nat(c) < 0 || let2nat(c) > ((int) ('z' - 'a') + 1) - 1) 
        {
            return c;
        } 
        else 
        {
            // do a safe shift
            int result = (let2nat(c) + shftAmt) % ((int) ('z' - 'a') + 1);
            result += ((int) ('z' - 'a') + 1);
            result %= ((int) ('z' - 'a') + 1);
            return nat2let(result);
         }
    }

    //encodes a string using the given shift amount
    static String encode(int shftAmt, String str)
    {
      char[] encodedStr = new char[str.length()];
      for(int i = 0; i < str.length(); i++)
      {
          encodedStr[i] = shift(shftAmt, str.charAt(i));
      }

      return new String(encodedStr);
    }

    //performs the inverse method to encode
    static String decode(int shftAmt, String str)
    {
      char[] decodedStr = new char[str.length()];
      for(int i = 0; i < str.length(); i++)
      {
          decodedStr[i] = shift(0 - shftAmt, str.charAt(i));
      }

      return new String(decodedStr);
    }

    //Calculates the amount of lowercase letters
    static int lowers(String str)
    {
      int count = 0;
      for(int i = 0; i < str.length(); i++)
      {
          if(let2nat(str.charAt(i)) >= 0 && let2nat(str.charAt(i)) <= 25)
              count++;
      }

      return count;
    }

    //Calculates the number of times a character appears in a string
    static int count(char c, String str)
    {
      int counter = 0;
      for(int i = 0; i < str.length(); i++)
      {
          if(c == str.charAt(i))
              counter++;
      }
      return counter;
    }

    //Calculates the percentage of one integer to another
    static double percent(int num1, int num2)
    {
      return ((float) num1/num2 * 100);
    }

    //Returns the list of percentage frequencies 
    static double[] freqs(String str)
    {
      double[] count = new double[26];
      for(int i = 0; i < str.length(); i++)
          if(let2nat(str.charAt(i)) >= 0 && let2nat(str.charAt(i)) <= 25)
              count[let2nat(str.charAt(i))]++;
      for(int i = 0; i < 26; i++)
          count[i] = percent((int)count[i], lowers(str));
      return count;
    }
}

上面是我到目前为止的代码，直到弄清楚频率..在执行以下操作时，我当前的输出是[D@2a139a55System.out.println(freqs("haskellisfun "));

当以下方法的输出应为:

that returns the list of percentage frequencies of each of the lower-case letters
’a’ to ’z’ in a string of characters. For example:
freqs("haskellisfun") ->
{8.33333,0.0,0.0,0.0,8.33333,8.33333,0.0,8.33333,
8.33333,0.0,8.33333,16.6667,0.0,8.33333,0.0,0.0,
0.0,0.0,16.6667,0.0,8.33333,0.0,0.0,0.0,0.0,0.0}

任何帮助将不胜感激，只是找不到我的错误。

Answer 1

打印的是数组的类型和哈希码。 ([D@2a139a55 表示“带有哈希码 2a139a55 的double 数组”)

您可以使用 Arrays.toString() 打印数组像这样:

import java.util.Arrays;
System.out.println(Arrays.toString(freqs("haskellisfun")));