Writing this program that reads a textfile with bunch of names. I need to track the instance of each letter. I don't know if theres a simpler way of doing this than what I have without using anything like hashMap. My problem here is that by doing this the long way I'm storing the frequencies in a String list rather than a more logical integer list? I'm not sure how I would get the max min if the index in my list contains the string and the integer value assigned to it.
import java.io.*;
import java.util.*;
public class CountInstances {
public static void main(String [] args) throws IOException{
ArrayList<String> list = new ArrayList<String>();//stores textfile into a list
ArrayList<String> frequencies = new ArrayList<String>(); //stores the number of instances for each letter
list = readFile("test.txt");
// System.out.println(list);
frequencies = letterInstances("test.txt");
// System.out.println(frequencies);
outputFile("test.txt", frequencies);
}//end of main
public static ArrayList<String> readFile(String file) throws IOException{
ArrayList<String> list = new ArrayList<String>();
Scanner reader = new Scanner(new File("test.txt"));//scanner accesses file
while(reader.hasNext()){//loops till end of all lines
String line = reader.nextLine();//scanner reads each line
list.add(line);//adds each line to the arrayList
}
return(list);
}//end of readFile method
public static ArrayList<String> letterInstances(String file)throws IOException{
ArrayList<String> instanceList = new ArrayList<String>();
Scanner reader = new Scanner(new File("test.txt"));//scanner accesses file
int frequencyA = 0;
int frequencyB = 0;
int frequencyC = 0;
int frequencyD = 0;
int frequencyE = 0;
int frequencyF = 0;
int frequencyG = 0;
int frequencyH = 0;
int frequencyI = 0;
int frequencyJ = 0;
int frequencyK = 0;
int frequencyL = 0;
int frequencyM = 0;
int frequencyN = 0;
int frequencyO = 0;
int frequencyP = 0;
int frequencyQ = 0;
int frequencyR = 0;
int frequencyS = 0;
int frequencyT = 0;
int frequencyU = 0;
int frequencyV = 0;
int frequencyW = 0;
int frequencyX = 0;
int frequencyY = 0;
int frequencyZ = 0;
while(reader.hasNext()){
String line = reader.nextLine();
for(int i = 0; i< line.length(); i ){
if(line.charAt(i) == 'A' || line.charAt(i) == 'a'){//if letter is found in line, increase counter by 1
frequencyA ;
}else if(line.charAt(i) == 'B' || line.charAt(i) == 'b'){
frequencyB ;
}else if(line.charAt(i) == 'C' || line.charAt(i) == 'c'){
frequencyC ;
}else if(line.charAt(i) == 'D' || line.charAt(i) == 'd'){
frequencyD ;
}else if(line.charAt(i) == 'E' || line.charAt(i) == 'e'){
frequencyE ;
}else if(line.charAt(i) == 'F' || line.charAt(i) == 'f'){
frequencyF ;
}else if(line.charAt(i) == 'G' || line.charAt(i) == 'g'){
frequencyG ;
}else if(line.charAt(i) == 'H' || line.charAt(i) == 'h'){
frequencyH ;
}else if(line.charAt(i) == 'I' || line.charAt(i) == 'i'){
frequencyI ;
}else if(line.charAt(i) == 'J' || line.charAt(i) == 'j'){
frequencyJ ;
}else if(line.charAt(i) == 'K' || line.charAt(i) == 'k'){
frequencyK ;
}else if(line.charAt(i) == 'L' || line.charAt(i) == 'l'){
frequencyL ;
}else if(line.charAt(i) == 'M' || line.charAt(i) == 'm'){
frequencyM ;
}else if(line.charAt(i) == 'N' || line.charAt(i) == 'n'){
frequencyN ;
}else if(line.charAt(i) == 'O' || line.charAt(i) == 'o'){
frequencyO ;
}else if(line.charAt(i) == 'P' || line.charAt(i) == 'p'){
frequencyP ;
}else if(line.charAt(i) == 'Q' || line.charAt(i) == 'q'){
frequencyQ ;
}else if(line.charAt(i) == 'R' || line.charAt(i) == 'r'){
frequencyR ;
}else if(line.charAt(i) == 'S' || line.charAt(i) == 's'){
frequencyS ;
}else if(line.charAt(i) == 'T' || line.charAt(i) == 't'){
frequencyT ;
}else if(line.charAt(i) == 'U' || line.charAt(i) == 'u'){
frequencyU ;
}else if(line.charAt(i) == 'V' || line.charAt(i) == 'v'){
frequencyV ;
}else if(line.charAt(i) == 'W' || line.charAt(i) == 'w'){
frequencyW ;
}else if(line.charAt(i) == 'X' || line.charAt(i) == 'x'){
frequencyX ;
}else if(line.charAt(i) == 'Y' || line.charAt(i) == 'y'){
frequencyY ;
}else if(line.charAt(i) == 'Z' || line.charAt(i) == 'z'){
frequencyZ ;
}
}
}
(Below) Storing this section into a String Array List won't let me get the individual values that I need to access in a separate method. Not storing it into a String array list would just list the values but I would not know for what letter it represents.
instanceList.add("A" frequencyA);
instanceList.add("B = " frequencyB);
instanceList.add("C = " frequencyC);
instanceList.add("D = " frequencyD);
instanceList.add("E = " frequencyE);
instanceList.add("F = " frequencyF);
instanceList.add("G = " frequencyG);
instanceList.add("H = " frequencyH);
instanceList.add("I = " frequencyI);
instanceList.add("J = " frequencyJ);
instanceList.add("K = " frequencyK);
instanceList.add("L = " frequencyL);
instanceList.add("M = " frequencyM);
instanceList.add("N = " frequencyN);
instanceList.add("O = " frequencyO);
instanceList.add("P = " frequencyP);
instanceList.add("Q = " frequencyQ);
instanceList.add("R = " frequencyR);
instanceList.add("S = " frequencyS);
instanceList.add("T = " frequencyT);
instanceList.add("U = " frequencyU);
instanceList.add("V = " frequencyV);
instanceList.add("W = " frequencyW);
instanceList.add("X = " frequencyX);
instanceList.add("Y = " frequencyY);
instanceList.add("Z = " frequencyZ);
return(instanceList);
}//end of letter instance method
Not sure what to go about here for getting the highest frequency and in descending order
public static void outputFile(String file, ArrayList<String> list)throws IOException{
PrintWriter writer = new PrintWriter(new File("frequencies.txt"));//prints output to new file
writer.println(letterInstances("test.txt" "\n"));//prints the frequency of each letter
System.out.println("An output file was created");
int largest = list.indexOf(1);//this index output would get the whole line ex. A = 9 (but I just need to track the number)
for(int i = 0; i < list.size(); i ){
writer.println("Top 5 Letters: ");
writer.close();
}
}
}//end of class
CodePudding user response：
If you can not use a HashMap, you can try this.
Comments in the code.
Code
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
*
* @author Sedrick(sedj601)
*/
public class Main
{
public static void main(String[] args)
{
//Fake file data
String dataToRead =
"""
Lorem Ipsum is simply dummy text of the
printing and typesetting industry Lorem
Ipsum has been the industrys standard dummy
text ever since thes when an unknown printer
took a galley of type and scrambled it to make a
type specimen book It has survived not only five
centuries but also the leap into electronic typesetting
remaining essentially unchanged It was popularised in the
a with the release of Letraset sheets containing
Lorem Ipsum passages and more recently with desktop
publishing software like Aldus PageMaker including
versions of Lorem Ipsum
""";
List<String> data = Arrays.asList(dataToRead.toUpperCase().split("\n"));//Capatilize the data as you read it.
List<String> keyCapitalLetters = Arrays.asList("ABCDEFGHIJKLMNOPQRSTUVWXYZ ".split(""));//Use this List like you would use the key part of a HashMap.
//data.forEach(System.out::println);
List<Integer> valuescounters = new ArrayList();//Use this list like you would use the value part of a HashMap
//Set all the counters values to zero.
for(int i = 0; i < 27; i )
{
valuescounters.add(0);
}
//Process the fake data line by line
for(String line : data)
{
System.out.println("Line: " line);
for(int i = 0; i < line.length(); i )//Read each character of each line.
{
int index = keyCapitalLetters.indexOf(String.valueOf(line.charAt(i)));//find the index in the key List of the characters that is being read.
valuescounters.set(index, valuescounters.get(index) 1);//Increment the counter value in the value list.
System.out.println("Char: " line.charAt(i) "\tIndex: " index);
}
}
//Print the output of the key and value list.
for(int i = 0; i < keyCapitalLetters.size(); i )
{
System.out.println(keyCapitalLetters.get(i) ": " valuescounters.get(i));
}
}
}
OutPut
A: 30
B: 5
C: 10
D: 16
E: 59
F: 6
G: 11
H: 14
I: 38
J: 0
K: 7
L: 22
M: 19
N: 38
O: 25
P: 19
Q: 0
R: 24
S: 38
T: 43
U: 17
V: 5
W: 6
X: 2
Y: 13
Z: 0
: 78
CodePudding user response：
Yes. You are right. You can use a hashmap. Try this code ->
public static Hashmap<String, Integer> letterInstances(String file)throws IOException{
Hashmap<String, String> instanceMap = Hashmap<String, String>;
Scanner reader = new Scanner(new File("test.txt"));//scanner accesses file
while(reader.hasNext()){
String line = reader.nextLine();
for(int i = 0; i< line.length(); i ){
String character = line.get(i).toString().toLowerCase();
int count = 0;
if(instanceMap.containsKey(character)) count = instanceList.get(character);
instanceMap.put(character, count)
}
return instanceMap;
}
Or if you also want to sort them to get the first 5 results, use this ->
public List<Entry<String, Integer>> getTop5(Hashmap map){
Set<Entry<String, Integer>> set = map.entrySet();
List<Entry<String, Integer>> list = new ArrayList<Entry<String, Integer>>(
set);
Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {
@Override
public int compare(Entry<String, Integer> o1,
Entry<String, Integer> o2) {
return o2.getValue().compareTo(o1.getValue());
}
});
System.out.println(list.subList(0, 5)); // this is the list of largest 5 characters in count
return list.subList(0, 5);
}