- Example:
- You are given the following text file:
WE hold these Truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the Pursuit of Happiness.
- You must produce the following result:
WE hold these Truths to be certain unalienable Rights, self-evident, that all Men are that among these are Life, created equal, that they are Liberty and the Pursuit of endowed by their Creator with Happiness.
- You are given the following text file:
- There are 3 major differences between
humans and machines:
- Flexibility
- Flexibility
- Flexibility
(Yeah, I got this sales pitch from my real estate agent :-))
- Manifestation of the differences
between humans and computers:
- Humans can work with
information stored
in any form or shape
- Computers must
arrange the
storage of the information
in a
form that is adequate (suitable)
for the algorithm
- The complexity (difficulty) of a computer algorithm depends heavily on the data structure used to stored the information that is used by the algorithm.
- Humans can work with
information stored
in any form or shape
- The first step in every computer
algorithm is a
direct result of the
differences between
humans and
machines
- The first step in
every computer algorithm is:
- Read in the
input data needed to solve the
problem
- Store the input data in such a way that will help make the algorithm easier to write.
- Read in the
input data needed to solve the
problem
- First thing we must do is:
- Design (decide on) a
data structure (way to store information)
for the
input (text) for the
text formatting problem
- The way that the information is stored must help us write/formulate the text formatting algorithm !!!
- Design (decide on) a
data structure (way to store information)
for the
input (text) for the
text formatting problem
- Observation:
- The text formatting algorithm
will manipulate
words
(We will not break a word with hyphenization...
E.g., we will not break iceberg into ice- and berg)
Therefore:
- Store the input text as
an array of String
(Each word in the input is a String stored in an array element)
- The text formatting algorithm
will manipulate
words
- Example:
- Input file:
WE hold these Truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the Pursuit of Happiness.
- Stored as:
String[] words = new String[10000]; int numWords = 35 word[0] = "WE" word[1] = "hold" word[2] = "these" word[3] = "Truths" word[4] = "to" word[5] = "be" word[6] = "self-evident," word[7] = "that" word[8] = "all" word[9] = "Men" word[10] = "are" word[11] = "created" word[12] = "equal," word[13] = "that" word[14] = "they" word[15] = "are" word[16] = "endowed" word[17] = "by" word[18] = "their" word[19] = "Creator" word[20] = "with" word[21] = "certain" word[22] = "unalienable" word[23] = "Rights," word[24] = "that" word[25] = "among" word[26] = "these" word[27] = "are" word[28] = "Life," word[29] = "Liberty" word[30] = "and" word[31] = "the" word[32] = "Pursuit" word[33] = "of" word[34] = "Happiness."
- Input file:
- Algorithm in pseudo code:
Open the file Create a "Scanner" to read data Read the input file into an array of String Note: we must remember the number of words read !
- Program in Java:
import java.io.*; import java.util.Scanner; public class FormatText1 { public static String[] words = new String[10000]; // Hold words in input file public static int numWords; // Count # words in input /* =========================================================== readInput(in, w): read words from input "in" into array w and return the #words read ============================================================ */ public static int readInput( Scanner in, String[] w ) { int nWords = 0; String x; while ( in.hasNext() ) { x = in.next(); // Read next word w[nWords] = x; // Store it away nWords++; // Count # words AND use next // array element to store next word } return ( nWords ); } public static void main(String[] args) throws IOException { if ( args.length == 0 ) { System.out.println( "Usage: java FormatText1 inputFile"); System.exit(1); } File myFile = new File( args[0] ); // Open file "inp2" Scanner in = new Scanner(myFile); // Make Scanner obj with opened file /* ---------------------------- Read input from data file ---------------------------- */ numWords = readInput( in, words ); } }
- Example Program:
(Demo above code)
- Prog file:
click here
- Input file 1 (small): click here
- Input file 2 (large): click here
How to run the program:
- Right click on link and
save in a scratch directory
- To compile: javac FormatText1.java
- To run:
java FormatText1 inp1
Or: java FormatText1 inp2
- Prog file:
click here