Please answer question correctly and show the result of the working code. The ac
ID: 3870322 • Letter: P
Question
Please answer question correctly and show the result of the working code. The actual and demo code is provided .
This assignment is about using the Java Collections Framework to accomplish some basic text-processing tasks.
These questions involve choosing the right abstraction (Collection, Set, List, Queue, Deque, SortedSet, Map, or SortedMap) to efficiently accomplish the task at hand. The best way to do these is to read the question and then think about what type of Collection is best to use to solve it. There are only a few lines of code you need to write to solve each of them.
Unless specified otherwise, sorted order refers to the natural sorted order on Strings, as defined by String.compareTo(s).
Que:Read the entire input one line at a time, and then output any subsequence of the lines that appear in the same order as they appear in the file which are also in non-decreasing or non-increasing sorted order. If the file contains n lines, then the length of this subsequence should be at least sqrt(n). For example, if the input contains 9 lines with the numbers:
2, 1, 3, 7, 4, 6, 9, 5, 8
then your output should have at least 3 lines, which could be 1,3,4 (increasing) or 2,3,7 (increasing) or 1,4,6,9 (increasing) or 2,6,8 (increasing) or 7,6,5 (decreasing) or ... . Warning/Hint: This is probably the hardest question. You're being asked to implement the Erds–Szekeres theorem.
Actual Code
package comp2402a1;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
public class Part10 {
/**
* Your code goes here - see Part0 for an example
* @param r the reader to read from
* @param w the writer to write to
* @throws IOException
*/
public static void doIt(BufferedReader r, PrintWriter w) throws IOException {
// Your code goes here - see Part0 for an example
}
/**
* The driver. Open a BufferedReader and a PrintWriter, either from System.in
* and System.out or from filenames specified on the command line, then call doIt.
* @param args
*/
public static void main(String[] args) {
try {
BufferedReader r;
PrintWriter w;
if (args.length == 0) {
r = new BufferedReader(new InputStreamReader(System.in));
w = new PrintWriter(System.out);
} else if (args.length == 1) {
r = new BufferedReader(new FileReader(args[0]));
w = new PrintWriter(System.out);
} else {
r = new BufferedReader(new FileReader(args[0]));
w = new PrintWriter(new FileWriter(args[1]));
}
long start = System.nanoTime();
doIt(r, w);
w.flush();
long stop = System.nanoTime();
System.out.println("Execution time: " + 10e-9 * (stop-start));
} catch (IOException e) {
System.err.println(e);
System.exit(-1);
}
}
}
Demo Code
package comp2402a1;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
public class Part0 {
/**
* Read lines one at a time from r. After reading all lines, output
* all lines to w, outputting duplicate lines only once. Note: the order
* of the output is unspecified and may have nothing to do with the order
* that lines appear in r.
* @param r the reader to read from
* @param w the writer to write to
* @throws IOException
*/
public static void doIt(BufferedReader r, PrintWriter w) throws IOException {
Set<String> s = new HashSet<>();
for (String line = r.readLine(); line != null; line = r.readLine()) {
s.add(line);
}
for (String text : s) {
w.println(text);
}
}
/**
* The driver. Open a BufferedReader and a PrintWriter, either from System.in
* and System.out or from filenames specified on the command line, then call doIt.
* @param args
*/
public static void main(String[] args) {
try {
BufferedReader r;
PrintWriter w;
if (args.length == 0) {
r = new BufferedReader(new InputStreamReader(System.in));
w = new PrintWriter(System.out);
} else if (args.length == 1) {
r = new BufferedReader(new FileReader(args[0]));
w = new PrintWriter(System.out);
} else {
r = new BufferedReader(new FileReader(args[0]));
w = new PrintWriter(new FileWriter(args[1]));
}
long start = System.nanoTime();
doIt(r, w);
w.flush();
long stop = System.nanoTime();
System.out.println("Execution time: " + 10e-9 * (stop-start));
} catch (IOException e) {
System.err.println(e);
System.exit(-1);
}
}
}
Explanation / Answer
/*
Complete code is given below. Please make sure to pass the input correctly.
There are 2 ways.
1. You save the input lines a file and pass the file name as command line argument to the program
2. You simply run the program without command line arguments. In this case, you can type lines on console.To stop entering more lines, press enter and in the newline press Ctrl+D
The output shown below is by using command line argument i.e passing the filename to program.
*/
package comp2402a1;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.SortedSet;
import java.util.TreeSet;
public class Part9 {
/**
* Your code goes here - see Part0 for an example
* @param r the reader to read from
* @param w the writer to write to
* @throws IOException
*/
public static void doIt(BufferedReader r, PrintWriter w) throws IOException {
SortedSet<String> set = new TreeSet<String>();
for (String line = r.readLine(); line != null; line = r.readLine()) {
boolean prefix = false;
//check if the line is a prefix of any of previous lines
for(String s : set)
{
if(s.startsWith(line)) //check if the string s begins with line
{
prefix = true;
break;
}
else if(s.compareTo(line) > 0) //already reached a line that is greater than the search
break;
}
if(!prefix)// if line is not prefix of any previous , then add to set
set.add(line);
}
for (String text : set) {
w.println(text);
}
}
/**
* The driver. Open a BufferedReader and a PrintWriter, either from System.in
* and System.out or from filenames specified on the command line, then call doIt.
* @param args
*/
public static void main(String[] args) {
try {
BufferedReader r;
PrintWriter w;
if (args.length == 0) {
r = new BufferedReader(new InputStreamReader(System.in));
w = new PrintWriter(System.out);
} else if (args.length == 1) {
r = new BufferedReader(new FileReader(args[0]));
w = new PrintWriter(System.out);
} else {
r = new BufferedReader(new FileReader(args[0]));
w = new PrintWriter(new FileWriter(args[1]));
}
long start = System.nanoTime();
doIt(r, w);
w.flush();
long stop = System.nanoTime();
System.out.println("Execution time: " + 10e-9 * (stop-start));
} catch (IOException e) {
System.err.println(e);
System.exit(-1);
}
}
}
input file: input.txt
helpful
help
richer
comedy
starter
rich
come
greater
great
star
output
comedy
greater
helpful
richer
starter
Execution time: 0.01877484