计算字母频率,也涉及双字母

时间:2014-11-27 23:28:16

标签: java character frequency letters

我有一项任务,我必须在Java中使用GUI的用户找到给定文本中的字母频率。问题是我是阿尔巴尼亚人,我们的字母表有36个字母:a,b,c ......等等,但也有'dh''ll''nj''th''xh''zh''''''''''。

我应该使用'if'来比较下一个字母:如果我有'd'而下一个是'h'我认为它是一个字母'dh'并找到它的频率? Java中还有其他方法吗?最后两个字母怎么样? Java会将它们识别为字符吗? 感谢。

1 个答案:

答案 0 :(得分:1)

您需要使用支持Unicode的方法,例如Character.isLetter()。以下是http://rosettacode.org/wiki/Letter_frequency#Java

的代码
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.Arrays;

public class LetterFreq {
    public static int[] countLetters(String filename) throws IOException{
        int[] freqs = new int[26];
        BufferedReader in = new BufferedReader(new FileReader(filename));
        String line;
        while((line = in.readLine()) != null){
            line = line.toUpperCase();
            for(char ch:line.toCharArray()){
                if(Character.isLetter(ch)){
                    freqs[ch - 'A']++;
                }
            }
        }
        in.close();
        return freqs;
    }

    public static void main(String[] args) throws IOException{
        System.out.println(Arrays.toString(countLetters("filename.txt")));
    }
}

这里我修改了它以包含Unicode字符

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class LetterFreq {
    public static Map<Character, Integer> countLetters(String filename) throws IOException{
        Map<Character, Integer> freqs = new HashMap<Character, Integer>();
        BufferedReader in = new BufferedReader(new FileReader(filename));
        String line;
        Integer f;
        while((line = in.readLine()) != null){
            line = line.toUpperCase();
            for(Character ch:line.toCharArray()){
                if(Character.isLetter(ch)){
                    f = freqs.get(ch);
                    if (f == null) {
                        freqs.put(ch, 0);   
                    }
                    else {
                        freqs.put(ch, ++f);
                    }
                }
            }
        }
        in.close();
        return freqs;
    }

    public static void main(String[] args) throws IOException{
        Map<Character, Integer> freqs = countLetters("filename.txt");
        Set<Character> keySet = freqs.keySet();
        for (Character key : keySet) {
                    System.out.println("Char: " + key + "  Count: " + freqs.get(key));
        }

    }
}