Question

6.15 Program 6: Using Arrays to Count Letters in Text

1. Introduction

In this program, you will practice working with arrays. Your program will read lines of text from the keyboard and use an array to track the number of times each letter occurs in the input text. You will use the contents of this array to generate a histogram (bar graph) indicating the relative frequencies of each letter entered.

Test cases are available in this document.

Remember, in addition to submitting your code, you MUST complete the Blackboard assignment "Program 6 style assessment" to get all of the points for this program. You can complete this "assignment" by typing a short message indicating you submitted your code through the textbook IDE.

2. Specification

Note: As discussed in class, there are a couple of inefficient brute-force methods to determine which letter is entered. (These prohibited methods are described in Section 3, Hints.) Using either method will incur a 10 point deduction.

Note 2: As also discussed in class, this program should not use strings.

Program Variables

At a minimum, you will need variables in main() to track:

• The number of times each letter in the alphabet has occurred in the input. These values should be stored in an array, in which the first entry represents the number of 'A' or 'a' characters entered, and the last entry represents the number of 'Z' or 'z' characters entered.
  • For example, if your first input is: Hello World!, the array should hold: {0,0,0,1,1,0,0,1,0,0,0,3,0,0,2,0,0,1,0,0,0,0,1,0,0,0}.
  • The non-zero values indicate the number of 'D', 'E', 'H', 'L', 'O', 'R', and 'W' characters entered, respectively.
  • Note that the character inputs are case-insensitive—uppercase and lowercase letters are treated the same.
• The maximum number of times any letter occurred—3, in the example above.

These variables are updated every time the user enters the 'R' command followed by a line of input, and reset to 0 every time the user enters the 'C' command. They are used to print the histogram whenever the ‘P’ command is used.

The variables should be updated inside the ReadText() function, and printed using the DrawHist() function.

Program Structure

Your program should repeatedly prompt the user to enter a single character command until the user enters the “quit” command. The program should perform the following operations for the listed commands:

• 'C', 'c': Clear the letter counts to 0 in preparation for analyzing new text.
• 'R', 'r': Read one line of text from the keyboard. Update the letter counts appropriately, using the ReadText() function.
• 'P', 'p': Plot the histogram of letter frequencies in all lines of text entered since the last 'C' command, using the DrawHist() function.
• 'Q', 'q': Quit—exit the program.

Functions

Your program should contain the functions described below, as well as any other functions you choose to add. Prototypes for these functions should be in prog6_functions.h, while their definitions should be written in prog6_functions.c:

• void ReadText(int histo[], int *max); Read one line of text from the keyboard, updating the array histo[] with the number of occurrences of each letter of the alphabet. Also, use the pointer max to update the variable holding the number of occurrences of the most frequent letter.
• void DrawHist(int histo[], int max); Given the array holding the letter counts (histo[]) and the number of occurrences of the most frequent letter (max), plot a histogram of the letter counts. Note that:
  • max helps you determine the height of the histogram, and therefore the number of rows to print.
  • When printing each row, print a vertical bar and a space "| " in the appropriate column if the letter count is large enough to be displayed in that row. Print two spaces otherwise.
  • Remember to leave spaces between columns—your output should line up exactly as shown in the test cases.
  • Remember that you are printing from the top of the histogram to the bottom—that fact will affect the design of this function.

See the test cases that demonstrate the proper format for input and output.

3. Hints

ASCII values

Recall that each character has a corresponding integer value, according to the ASCII standard. You may find it useful to work directly with ASCII values in this program, rather than testing if each input character matches a particular letter. 'A' has the ASCII value 65; 'a' has the ASCII value 97.

Character functions

You may find the following built-in functions from the <ctype.h> library useful. Remember that int and char data types are compatible:

• int isalpha(int ch): This function returns a non-zero value if ch is a letter of the alphabet, and zero otherwise.
  • For example, isalpha('Q') returns a non-zero value; isalpha('3') returns 0.
• int tolower(int ch): If ch is an uppercase letter, this function returns the lowercase version. Otherwise, tolower() returns the original value of ch.
  • For example, tolower('Q') returns 'q'; tolower('a') returns 'a'.
• int toupper(int ch): If ch is a lowercase letter, this function returns the uppercase version. Otherwise, tolower() returns the original value of ch.
  • For example, toupper('q') returns 'Q'; toupper('A') returns 'A'.

Prohibited brute force methods

Brute force methods are inefficient solutions to problems. Such a method can be used to determine which letter was entered and update the appropriate array entry, but I want you to find a more efficient solution. Using a brute force method like the following will therefore incur a 10 point deduction.

Again, each of the following is an example of what NOT to do:

• Large switch (or if) statement: one case for each letter, with array index as a known constant in each case:

switch(ch) {            // ch = input char
case ‘A’: case ‘a’:
    // modify histo[0]
    break;
case ‘B’: case ‘b’:
    // modify histo[1]
    break;

    // Remainder of cases
}

• Loop: compares input character against all possible letters, using loop index as array index:

char test = ‘A’;
for (i = 0; i < 26; i++) {
    if (ch == test)
        // modify histo[i]
    test++;     // Change test 
}                //  to next letter

Note: Each brute force method essentially compares the input character against all possible letters. However, once you know the input character is a letter, you do not need to compare it to anything to determine what array entry to update! There’s a simple “transformation” between the ASCII value of each letter and the corresponding index in the histogram array.

Answer 1

find the java code to count the number of letters, lines, space and paragraph in a text:-

import java.io.*; 

public class Test 
{ 
        public static void main(String[] args) throws IOException 
        { 
                File file = new File("Path_of _file"); 
                FileInputStream fileStream = new FileInputStream(file); 
                InputStreamReader input = new InputStreamReader(fileStream); 
                BufferedReader reader = new BufferedReader(input); 
                
                String line; 

                int countWord = 0; 
                int sentenceCount = 0; 
                int characterCount = 0; 
                int paragraphCount = 1; 
                int whitespaceCount = 0; 
                
                while((line = reader.readLine()) != null) 
                { 
                        if(line.equals("")) 
                        { 
                                paragraphCount++; 
                        } else { 
                                characterCount += line.length(); 
                                
                                String[] wordList = line.split("\\s+"); 
                                
                                countWord += wordList.length; 
                                whitespaceCount += countWord -1; 

                                String[] sentenceList = line.split("[!?.:]+"); 
                                
                                sentenceCount += sentenceList.length; 
                        } 
                } 
                
                System.out.println("Total word count = " + countWord); 
                System.out.println("Total number of sentences = " + sentenceCount); 
                System.out.println("Total number of characters = " + characterCount); 
                System.out.println("Number of paragraphs = " + paragraphCount); 
                System.out.println("Total number of whitespaces = " + whitespaceCount); 
        } 
}