COS126

• Download FrequencyTable.java

/*****************************************************************************
 * Name:                                                                     *
 * NetID:                                                                    *
 * Precept:                                                                  *
 *                                                                           *
 * Description: Counts the repeated occurrences in a list of Strings.        *
 *                                                                           *
 * Example:                                                                  *
 * % java-introcs FrequencyTable                                             *
 * duck duck goose[Ctrl+D]                                                   *
 * 2 duck                                                                    *
 * 1 goose                                                                   *
 *                                                                           *
 * Remarks:                                                                  *
 *  - This is book exercise 4.4 #36 (Booksite Creative Ex 4.4 #5)            *
 *  - Use with mobydick.txt, available on the precepts page.                 *
 *****************************************************************************/

public class FrequencyTable {

    // maintain counts of all words seen so far
    // the key is the word and the value is the count
    private ST<_______________> st = _________________________;
   
    // remark: we have not declared a constuctor! but Java lets every class 
    // have a no-argument constructor by default. It only runs the line of 
    // code above (instance variable initialization).
   
    // increment the frequency of this word
    public void click(String word) {
        int count = count(word);
        st.put(word, count + 1);
    }
   
    // what is the frequency of this word?
    public int count(String word) {
        if (!st._____(___________)) return 0;  // if word is not in ST
        else return _____.______(__________);  // get word's count
    }
   
    // print words and their frequencies
    public void show() {

        // remark: this is called a "foreach loop" or an "enhanced for loop."
        // it goes through all keys in alphabetical order. this is the only
        // way to traverse a symbol table!

        for (String word : st.keys()) {
            // print frequency and word, separated by a space
            StdOut.println(_______________(______) + " " + ___________);
        }
    }
   
    // count all words in StdIn
    public static void main(String[] args) {
   
        FrequencyTable freq = new FrequencyTable();

        // build frequency table from words on standard input
        while (!StdIn.isEmpty()) {
            String word = StdIn.readString();
            freq.________(word);
        }
   
        // print frequency table to standard output
        freq.show();
    }
}