无法让我的 for 循环给我哈希图中最不常见的字母

Question

我有一切工作，除了我无法弄清楚为什么我的代码找不到最不常见的字母我有一个 for 循环，它应该找到最不常见的字母，但它没有给我任何东西。 它给了我最常见的，但并非最不重要的。

    FileReader file = new FileReader("\src\alphaCounter\");
    BufferedReader reader = new BufferedReader(file);
    HashMap<Character,Integer> myHashSet = new HashMap<Character, Integer>();
    myHashSet.put('a', 0);
    /** this goes to Z

    int mostCommon = 0;
    char mostCommonLtr = ' ';
    int leastCommont = 0;
    char leastCommonLtr = ' ';

    Object[] words = reader.lines().toArray();
    /**
     * this loop has changed all the letters to lower case
     */
    for(Object word : words){
        String wordString = word.toString();
        wordString = wordString.toLowerCase();
        /**
         * 
         */
        if(wordString.length() > bigWord.length()){
            bigWord = wordString;
        }    
        for(int alpha = 0; alpha < wordString.length(); alpha++){
            myHashSet.put(wordString.charAt(alpha), myHashSet.get(wordString.charAt(alpha)) + 1);
        }
    }
            for(int alpha = 'a'; alpha<= 'z'; alpha++){
        System.out.println("The number of " + (char)alpha +  "'s in the words.txt = " + myHashSet.get((char)alpha ));
        if(myHashSet.get((char)alpha) > mostCommon)  {
            mostCommonLtr = (char)alpha;
            mostCommon = myHashSet.get((char)alpha); 
            /**
             * this gave me the most common letter
             */

        if(myHashSet.get((char)alpha) < leastCommont)  {
            leastCommonLtr = (char)alpha;
            leastCommont = myHashSet.get((char)alpha);
            /**
             * this was supposed to give me the least common
             */
        }   
    }

    System.out.println("The letter that appeared the least is " + leastCommonLtr);  
    System.out.println("The letter that appears the most is " + mostCommonLtr); 

Answer 1

替换

int leastCommont = 0;

跟

int leastCommont = Integer.MAX_VALUE;

原因

将leastCommont初始化为 0 时，永远不会满足代码的以下条件：

if(myHashSet.get((char)alpha) < leastCommont)

Answer 2

  if(myHashSet.get((char)alpha) != null && myHashSet.get((char)alpha) > mostCommon)  {
                    mostCommonLtr = (char)alpha;
                    mostCommon = myHashSet.get((char)alpha); 
                    /**
                     * this gave me the most common letter
                     */
                } 
                if(myHashSet.get((char)alpha) != null && myHashSet.get((char)alpha) > leastCommont && alpha != mostCommonLtr )  {
                    leastCommonLtr = (char)alpha;
                    leastCommont = myHashSet.get((char)alpha);
                    /**
                     * this was supposed to give me the least common
                     */
            }

尝试使用上面的代码段。您在相同的 if 子句中获得了最高和最低。您需要以不同的方式处理它。从早期的代码来看，它甚至没有使用最少的字符。

Answer 3

我希望这段代码能帮助你。我做了一个简单的字符计数器。您可以使用此功能使函数成为您想要的函数。如果要不区分大小写，请将输入字符串设置为小写或大写。

    String wordString = "a1s3df2ad2fsa3dfwe3wrqasdf";
    System.out.println("input string="+wordString) ;
    char[] cword = wordString.toCharArray();
    List<Character> mylist = new ArrayList<Character>();
    Set<Character> charset = new HashSet<Character>();
    HashMap<Character, Integer> myHashSet = new HashMap<Character, Integer>();
    int maxcnt, mincnt;
    for (char c : cword) {
        mylist.add(c);
        charset.add(c);
    }
    for (Character c : charset) {
        int freq= Collections.frequency(mylist, c) ;
        System.out.println("alpha " + c + " freq="+freq );
        myHashSet.put(c, freq) ;
    }
    maxcnt = Collections.max(myHashSet.values()) ;
    mincnt = Collections.min(myHashSet.values()) ;
    System.out.println("maxcnt="+maxcnt+" mincnt="+mincnt) ;
    // get max alpha
    System.out.print("max count alphas: ") ;
    for (Character c : charset ) {
        if ( maxcnt == myHashSet.get(c).intValue() ) {
            System.out.print(" "+c);
        }
    }
    System.out.println("") ;
    // get min alpha
    System.out.print("min count alphas: ") ;
    for (Character c : charset ) {
        if ( mincnt == myHashSet.get(c).intValue() ) {
            System.out.print(" "+c);
        }
    }
    System.out.println("") ;

样本的输出

input string=a1s3df2ad2fsa3dfwe3wrqasdf
alpha a freq=4
alpha 1 freq=1
alpha q freq=1
alpha 2 freq=2
alpha r freq=1
alpha s freq=3
alpha 3 freq=3
alpha d freq=4
alpha e freq=1
alpha f freq=4
alpha w freq=2
maxcnt=4 mincnt=1
max count alphas:  a d f
min count alphas:  1 q r e