Cleaned up code for some packages (#5094)

* Cleaned up code of some packages

---------

Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com>

src/main/java/com/thealgorithms/conversions/IntegerToRoman.java

@@ -9,7 +9,7 @@ package com.thealgorithms.conversions;
  */
 public class IntegerToRoman {
 
-    private static int[] allArabianRomanNumbers = new int[] {
+    private static final int[] allArabianRomanNumbers = new int[] {
         1000,
         900,
         500,
@@ -24,7 +24,7 @@ public class IntegerToRoman {
         4,
         1,
     };
-    private static String[] allRomanNumbers = new String[] {
+    private static final String[] allRomanNumbers = new String[] {
         "M",
         "CM",
         "D",

src/main/java/com/thealgorithms/conversions/RomanToInteger.java

@@ -4,9 +4,7 @@ import java.util.*;
 
 public class RomanToInteger {
 
-    private static Map<Character, Integer> map = new HashMap<Character, Integer>() {
-        /**
-         *          */
+    private static final Map<Character, Integer> map = new HashMap<>() {
         private static final long serialVersionUID = 87605733047260530L;
 
         {

src/main/java/com/thealgorithms/conversions/TurkishToLatinConversion.java

@@ -58,7 +58,7 @@ public class TurkishToLatinConversion {
             'G',
         };
         for (int i = 0; i < turkishChars.length; i++) {
-            param = param.replaceAll(new String(new char[] {turkishChars[i]}), new String(new char[] {latinChars[i]}));
+            param = param.replaceAll(String.valueOf(turkishChars[i]), String.valueOf(latinChars[i]));
         }
         return param;
     }

src/main/java/com/thealgorithms/dynamicprogramming/Fibonacci.java

@@ -9,7 +9,7 @@ import java.util.Scanner;
  */
 public class Fibonacci {
 
-    private static Map<Integer, Integer> map = new HashMap<>();
+    private static final Map<Integer, Integer> map = new HashMap<>();
 
     public static void main(String[] args) {
         // Methods all returning [0, 1, 1, 2, 3, 5, ...] for n = [0, 1, 2, 3, 4, 5, ...]
@@ -106,7 +106,6 @@ public class Fibonacci {
     public static int fibBinet(int n) {
         double squareRootOf5 = Math.sqrt(5);
         double phi = (1 + squareRootOf5) / 2;
-        int nthTerm = (int) ((Math.pow(phi, n) - Math.pow(-phi, -n)) / squareRootOf5);
-        return nthTerm;
+        return (int) ((Math.pow(phi, n) - Math.pow(-phi, -n)) / squareRootOf5);
     }
 }

src/main/java/com/thealgorithms/dynamicprogramming/MatrixChainMultiplication.java

@@ -6,8 +6,8 @@ import java.util.Scanner;
 
 public class MatrixChainMultiplication {
 
-    private static Scanner scan = new Scanner(System.in);
-    private static ArrayList<Matrix> mArray = new ArrayList<>();
+    private static final Scanner scan = new Scanner(System.in);
+    private static final ArrayList<Matrix> mArray = new ArrayList<>();
     private static int size;
     private static int[][] m;
     private static int[][] s;
@@ -115,9 +115,9 @@ public class MatrixChainMultiplication {
 
 class Matrix {
 
-    private int count;
-    private int col;
-    private int row;
+    private final int count;
+    private final int col;
+    private final int row;
 
     Matrix(int count, int col, int row) {
         this.count = count;

src/main/java/com/thealgorithms/greedyalgorithms/ActivitySelection.java

@@ -8,9 +8,9 @@ import java.util.Comparator;
 
 public class ActivitySelection {
     // Function to perform activity selection
-    public static ArrayList<Integer> activitySelection(int startTimes[], int endTimes[]) {
+    public static ArrayList<Integer> activitySelection(int[] startTimes, int[] endTimes) {
         int n = startTimes.length;
-        int activities[][] = new int[n][3];
+        int[][] activities = new int[n][3];
 
         // Create a 2D array to store activities and their start/end times.
         // Each row: [activity index, start time, end time]

src/main/java/com/thealgorithms/greedyalgorithms/CoinChange.java

@@ -10,12 +10,11 @@ public class CoinChange {
     // Function to solve the coin change problem
     public static ArrayList<Integer> coinChangeProblem(int amount) {
         // Define an array of coin denominations in descending order
-        Integer coins[] = {1, 2, 5, 10, 20, 50, 100, 500, 2000};
+        Integer[] coins = {1, 2, 5, 10, 20, 50, 100, 500, 2000};
 
         // Sort the coin denominations in descending order
         Arrays.sort(coins, Comparator.reverseOrder());
 
-        int count = 0; // Variable to keep track of the total number of coins used
         ArrayList<Integer> ans = new ArrayList<>(); // List to store selected coins
 
         // Iterate through the coin denominations
@@ -24,7 +23,6 @@ public class CoinChange {
             if (coins[i] <= amount) {
                 // Repeatedly subtract the coin denomination from the remaining amount
                 while (coins[i] <= amount) {
-                    count++; // Increment the count of coins used
                     ans.add(coins[i]); // Add the coin to the list of selected coins
                     amount -= coins[i]; // Update the remaining amount
                 }

src/main/java/com/thealgorithms/greedyalgorithms/FractionalKnapsack.java

@@ -7,9 +7,9 @@ import java.util.Comparator;
 
 public class FractionalKnapsack {
     // Function to perform fractional knapsack
-    public static int fractionalKnapsack(int weight[], int value[], int capacity) {
+    public static int fractionalKnapsack(int[] weight, int[] value, int capacity) {
         // Create a 2D array to store item indices and their value-to-weight ratios.
-        double ratio[][] = new double[weight.length][2];
+        double[][] ratio = new double[weight.length][2];
 
         // Populate the ratio array with item indices and their value-to-weight ratios.
         for (int i = 0; i < weight.length; i++) {

src/main/java/com/thealgorithms/greedyalgorithms/JobSequencing.java

@@ -31,7 +31,7 @@ public class JobSequencing {
         Boolean[] slots = new Boolean[size];
         Arrays.fill(slots, false);
 
-        int result[] = new int[size];
+        int[] result = new int[size];
 
         // Iterate through jobs to find the optimal job sequence
         for (int i = 0; i < size; i++) {

src/main/java/com/thealgorithms/searches/UnionFind.java

@@ -4,8 +4,8 @@ import java.util.*;
 
 public class UnionFind {
 
-    private int[] p;
-    private int[] r;
+    private final int[] p;
+    private final int[] r;
 
     public UnionFind(int n) {
         p = new int[n];

src/main/java/com/thealgorithms/sorts/DNFSort.java

@@ -7,7 +7,7 @@ public class DNFSort {
     static void sort012(int[] a, int arr_size) {
         int low = 0;
         int high = arr_size - 1;
-        int mid = 0, temp = 0;
+        int mid = 0, temp;
         while (mid <= high) {
             switch (a[mid]) {
             case 0: {
@@ -37,7 +37,7 @@ public class DNFSort {
         for (int i = 0; i < arr_size; i++) {
             System.out.print(arr[i] + " ");
         }
-        System.out.println("");
+        System.out.println();
     }
 
     /*Driver function to check for above functions*/

src/main/java/com/thealgorithms/strings/Pangram.java

@@ -25,12 +25,11 @@ public class Pangram {
      */
     // alternative approach using Java Collection Framework
     public static boolean isPangramUsingSet(String s) {
-        HashSet<Character> alpha = new HashSet<Character>();
+        HashSet<Character> alpha = new HashSet<>();
         s = s.trim().toLowerCase();
         for (int i = 0; i < s.length(); i++)
             if (s.charAt(i) != ' ') alpha.add(s.charAt(i));
-        if (alpha.size() == 26) return true;
-        return false;
+        return alpha.size() == 26;
     }
 
     /**