Merge branch 'master' into refactor/change_package

Author: alxkm

pmd-exclude.properties

@@ -12,7 +12,7 @@ com.thealgorithms.datastructures.crdt.LWWElementSet=UselessParentheses
 com.thealgorithms.datastructures.crdt.Pair=UnusedPrivateField
 com.thealgorithms.datastructures.graphs.AStar=UselessParentheses
 com.thealgorithms.datastructures.graphs.AdjacencyMatrixGraph=CollapsibleIfStatements,UnnecessaryFullyQualifiedName,UselessParentheses
-com.thealgorithms.datastructures.graphs.BipartiteGrapfDFS=CollapsibleIfStatements
+com.thealgorithms.datastructures.graphs.BipartiteGraphDFS=CollapsibleIfStatements
 com.thealgorithms.datastructures.graphs.Kruskal=UselessParentheses
 com.thealgorithms.datastructures.hashmap.hashing.HashMapCuckooHashing=UselessParentheses
 com.thealgorithms.datastructures.heaps.FibonacciHeap=UselessParentheses

pom.xml

@@ -50,7 +50,7 @@
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>
-            <version>3.16.0</version>
+            <version>3.17.0</version>
         </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>

src/main/java/com/thealgorithms/datastructures/graphs/BipartiteGrapfDFS.java renamed to src/main/java/com/thealgorithms/datastructures/graphs/BipartiteGraphDFS.java

@@ -14,8 +14,8 @@
  *
  * Output : YES
  */
-public final class BipartiteGrapfDFS {
-    private BipartiteGrapfDFS() {
+public final class BipartiteGraphDFS {
+    private BipartiteGraphDFS() {
     }
 
     private static boolean bipartite(int v, ArrayList<ArrayList<Integer>> adj, int[] color, int node) {

src/main/java/com/thealgorithms/datastructures/lists/MergeKSortedLinkedlist.java renamed to src/main/java/com/thealgorithms/datastructures/lists/MergeKSortedLinkedList.java

@@ -7,7 +7,7 @@
 /**
  * @author Arun Pandey (https://github.com/pandeyarun709)
  */
-public class MergeKSortedLinkedlist {
+public class MergeKSortedLinkedList {
 
     /**
      * This function merge K sorted LinkedList

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

@@ -1,46 +1,16 @@
 package com.thealgorithms.dynamicprogramming;
 
-/*
-* this is an important Algo in which
-* we have starting and ending of board and we have to reach
-* we have to count no. of ways
-* that help to reach end point i.e number by rolling dice
-* which have 1 to 6 digits
-
-Test Case:
-here target is 10
-
-int n=10;
-                startAlgo();
-                System.out.println(bpR(0,n));
-                System.out.println(endAlgo()+"ms");
-                int[] strg=new int [n+1];
-                startAlgo();
-                System.out.println(bpRS(0,n,strg));
-                System.out.println(endAlgo()+"ms");
-                startAlgo();
-                System.out.println(bpIS(0,n,strg));
-                System.out.println(endAlgo()+"ms");
-
-
-
- */
 public final class BoardPath {
     private BoardPath() {
     }
 
-    public static long startTime;
-    public static long endTime;
-
-    public static void startAlgo() {
-        startTime = System.currentTimeMillis();
-    }
-
-    public static long endAlgo() {
-        endTime = System.currentTimeMillis();
-        return endTime - startTime;
-    }
-
+    /**
+     * Recursive solution without memoization
+     *
+     * @param start - the current position
+     * @param end   - the target position
+     * @return the number of ways to reach the end from the start
+     */
     public static int bpR(int start, int end) {
         if (start == end) {
             return 1;
@@ -54,6 +24,14 @@ public static int bpR(int start, int end) {
         return count;
     }
 
+    /**
+     * Recursive solution with memoization
+     *
+     * @param curr - the current position
+     * @param end  - the target position
+     * @param strg - memoization array
+     * @return the number of ways to reach the end from the start
+     */
     public static int bpRS(int curr, int end, int[] strg) {
         if (curr == end) {
             return 1;
@@ -71,15 +49,23 @@ public static int bpRS(int curr, int end, int[] strg) {
         return count;
     }
 
+    /**
+     * Iterative solution with tabulation
+     *
+     * @param curr - the current position (always starts from 0)
+     * @param end  - the target position
+     * @param strg - memoization array
+     * @return the number of ways to reach the end from the start
+     */
     public static int bpIS(int curr, int end, int[] strg) {
         strg[end] = 1;
         for (int i = end - 1; i >= 0; i--) {
             int count = 0;
-            for (int dice = 1; dice <= 6 && dice + i < strg.length; dice++) {
+            for (int dice = 1; dice <= 6 && dice + i <= end; dice++) {
                 count += strg[i + dice];
             }
             strg[i] = count;
         }
-        return strg[0];
+        return strg[curr];
     }
 }

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

@@ -5,46 +5,32 @@ private SubsetSum() {
     }
 
     /**
-     * Driver Code
-     */
-    public static void main(String[] args) {
-        int[] arr = new int[] {50, 4, 10, 15, 34};
-        assert subsetSum(arr, 64);
-        /* 4 + 10 + 15 + 34 = 64 */
-        assert subsetSum(arr, 99);
-        /* 50 + 15 + 34 = 99 */
-        assert !subsetSum(arr, 5);
-        assert !subsetSum(arr, 66);
-    }
-
-    /**
-     * Test if a set of integers contains a subset that sum to a given integer.
+     * Test if a set of integers contains a subset that sums to a given integer.
      *
-     * @param arr the array contains integers.
-     * @param sum target sum of subset.
-     * @return {@code true} if subset exists, otherwise {@code false}.
+     * @param arr the array containing integers.
+     * @param sum the target sum of the subset.
+     * @return {@code true} if a subset exists that sums to the given value, otherwise {@code false}.
      */
     public static boolean subsetSum(int[] arr, int sum) {
         int n = arr.length;
-        boolean[][] isSum = new boolean[n + 2][sum + 1];
+        boolean[][] isSum = new boolean[n + 1][sum + 1];
 
-        isSum[n + 1][0] = true;
-        for (int i = 1; i <= sum; i++) {
-            isSum[n + 1][i] = false;
+        // Initialize the first column to true since a sum of 0 can always be achieved with an empty subset.
+        for (int i = 0; i <= n; i++) {
+            isSum[i][0] = true;
         }
 
-        for (int i = n; i > 0; i--) {
-            isSum[i][0] = true;
-            for (int j = 1; j <= arr[i - 1] - 1; j++) {
-                if (j <= sum) {
-                    isSum[i][j] = isSum[i + 1][j];
+        // Fill the subset sum matrix
+        for (int i = 1; i <= n; i++) {
+            for (int j = 1; j <= sum; j++) {
+                if (arr[i - 1] <= j) {
+                    isSum[i][j] = isSum[i - 1][j] || isSum[i - 1][j - arr[i - 1]];
+                } else {
+                    isSum[i][j] = isSum[i - 1][j];
                 }
             }
-            for (int j = arr[i - 1]; j <= sum; j++) {
-                isSum[i][j] = (isSum[i + 1][j] || isSum[i + 1][j - arr[i - 1]]);
-            }
         }
 
-        return isSum[1][sum];
+        return isSum[n][sum];
     }
 }

src/main/java/com/thealgorithms/maths/LeastCommonMultiple.java

@@ -1,41 +1,27 @@
 package com.thealgorithms.maths;
 
-import java.util.Scanner;
-
 /**
  * Is a common mathematics concept to find the smallest value number
  * that can be divide using either number without having the remainder.
  * https://maticschool.blogspot.com/2013/11/find-least-common-multiple-lcm.html
  * @author LauKinHoong
  */
-
 public final class LeastCommonMultiple {
     private LeastCommonMultiple() {
     }
 
     /**
-     * Driver Code
-     */
-    public static void main(String[] args) {
-        Scanner input = new Scanner(System.in);
-        System.out.println("Please enter first number >> ");
-        int num1 = input.nextInt();
-        System.out.println("Please enter second number >> ");
-        int num2 = input.nextInt();
-        System.out.println("The least common multiple of two numbers is >> " + lcm(num1, num2));
-        input.close();
-    }
-
-    /*
-     * get least common multiple from two number
+     * Finds the least common multiple of two numbers.
+     *
+     * @param num1 The first number.
+     * @param num2 The second number.
+     * @return The least common multiple of num1 and num2.
      */
     public static int lcm(int num1, int num2) {
         int high;
         int num3;
         int cmv = 0;
-        /*
-         * value selection for the numerator
-         */
+
         if (num1 > num2) {
             high = num1;
             num3 = num1;

src/main/java/com/thealgorithms/others/MaximumSumOfDistinctSubarraysWithLengthK.java

@@ -1,55 +1,53 @@
 package com.thealgorithms.others;
 
 import java.util.HashSet;
+import java.util.Set;
 
-/*
-References: https://en.wikipedia.org/wiki/Streaming_algorithm
-* In this model, the function of interest is computing over a fixed-size window in the stream. As the stream progresses,
-* items from the end of the window are removed from consideration while new items from the stream take their place.
-* @author Swarga-codes (https://github.com/Swarga-codes)
-*/
+/**
+ * References: https://en.wikipedia.org/wiki/Streaming_algorithm
+ *
+ * This model involves computing the maximum sum of subarrays of a fixed size \( K \) from a stream of integers.
+ * As the stream progresses, elements from the end of the window are removed, and new elements from the stream are added.
+ *
+ * @author Swarga-codes (https://github.com/Swarga-codes)
+ */
 public final class MaximumSumOfDistinctSubarraysWithLengthK {
     private MaximumSumOfDistinctSubarraysWithLengthK() {
     }
-    /*
-     * Returns the maximum sum of subarray of size K consisting of distinct
-     * elements.
-     *
-     * @param k size of the subarray which should be considered from the given
-     * array.
+
+    /**
+     * Finds the maximum sum of a subarray of size K consisting of distinct elements.
      *
-     * @param nums is the array from which we would be finding the required
-     * subarray.
+     * @param k The size of the subarray.
+     * @param nums The array from which subarrays will be considered.
      *
-     * @return the maximum sum of distinct subarray of size K.
+     * @return The maximum sum of any distinct-element subarray of size K. If no such subarray exists, returns 0.
      */
     public static long maximumSubarraySum(int k, int... nums) {
         if (nums.length < k) {
             return 0;
         }
-        long max = 0; // this will store the max sum which will be our result
-        long s = 0; // this will store the sum of every k elements which can be used to compare with
-                    // max
-        HashSet<Integer> set = new HashSet<>(); // this can be used to store unique elements in our subarray
-        // Looping through k elements to get the sum of first k elements
+        long masSum = 0; // Variable to store the maximum sum of distinct subarrays
+        long currentSum = 0; // Variable to store the sum of the current subarray
+        Set<Integer> currentSet = new HashSet<>(); // Set to track distinct elements in the current subarray
+
+        // Initialize the first window
         for (int i = 0; i < k; i++) {
-            s += nums[i];
-            set.add(nums[i]);
+            currentSum += nums[i];
+            currentSet.add(nums[i]);
         }
-        // Checking if the first kth subarray contains unique elements or not if so then
-        // we assign that to max
-        if (set.size() == k) {
-            max = s;
+        // If the first window contains distinct elements, update maxSum
+        if (currentSet.size() == k) {
+            masSum = currentSum;
         }
-        // Looping through the rest of the array to find different subarrays and also
-        // utilising the sliding window algorithm to find the sum
-        // in O(n) time complexity
+        // Slide the window across the array
         for (int i = 1; i < nums.length - k + 1; i++) {
-            s = s - nums[i - 1];
-            s = s + nums[i + k - 1];
+            // Update the sum by removing the element that is sliding out and adding the new element
+            currentSum = currentSum - nums[i - 1];
+            currentSum = currentSum + nums[i + k - 1];
             int j = i;
             boolean flag = false; // flag value which says that the subarray contains distinct elements
-            while (j < i + k && set.size() < k) {
+            while (j < i + k && currentSet.size() < k) {
                 if (nums[i - 1] == nums[j]) {
                     flag = true;
                     break;
@@ -58,17 +56,14 @@ public static long maximumSubarraySum(int k, int... nums) {
                 }
             }
             if (!flag) {
-                set.remove(nums[i - 1]);
+                currentSet.remove(nums[i - 1]);
             }
-            set.add(nums[i + k - 1]);
-            // if the subarray contains distinct elements then we compare and update the max
-            // value
-            if (set.size() == k) {
-                if (max < s) {
-                    max = s;
-                }
+            currentSet.add(nums[i + k - 1]);
+            // If the current window has distinct elements, compare and possibly update maxSum
+            if (currentSet.size() == k && masSum < currentSum) {
+                masSum = currentSum;
             }
         }
-        return max; // the final maximum sum
+        return masSum; // the final maximum sum
     }
 }

src/main/java/com/thealgorithms/stacks/LargestRectangle.java

@@ -11,7 +11,7 @@ public final class LargestRectangle {
     private LargestRectangle() {
     }
 
-    public static String largestRectanglehistogram(int[] heights) {
+    public static String largestRectangleHistogram(int[] heights) {
         int n = heights.length;
         int maxArea = 0;
         Stack<int[]> st = new Stack<>();
@@ -32,7 +32,7 @@ public static String largestRectanglehistogram(int[] heights) {
     }
 
     public static void main(String[] args) {
-        assert largestRectanglehistogram(new int[] {2, 1, 5, 6, 2, 3}).equals("10");
-        assert largestRectanglehistogram(new int[] {2, 4}).equals("4");
+        assert largestRectangleHistogram(new int[] {2, 1, 5, 6, 2, 3}).equals("10");
+        assert largestRectangleHistogram(new int[] {2, 4}).equals("4");
     }
 }

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

@@ -13,7 +13,6 @@ private ReverseWordsInString() {
      * @param s the input string
      * @return A string created by reversing the order of the words in {@code s}
      */
-
     public static String reverseWordsInString(final String s) {
         var words = s.trim().split("\\s+");
         Collections.reverse(Arrays.asList(words));

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

@@ -15,13 +15,13 @@ public static void main(String[] args) {
     }
 
     /**
-     * Converts all of the characters in this {@code String} to upper case
+     * Converts all the characters in this {@code String} to upper case
      *
      * @param s the string to convert
      * @return the {@code String}, converted to uppercase.
      */
     public static String toUpperCase(String s) {
-        if (s == null || "".equals(s)) {
+        if (s == null || s.isEmpty()) {
             return s;
         }
         char[] values = s.toCharArray();