TheAlgorithms · yanglbme · Jun 9, 2023 · Jun 9, 2023
@@ -22,9 +22,7 @@ public class IIRFilter {
      */
     public IIRFilter(int order) throws IllegalArgumentException {
         if (order < 1) {
-            throw new IllegalArgumentException(
-                "order must be greater than zero"
-            );
+            throw new IllegalArgumentException("order must be greater than zero");
         }
 
         this.order = order;
@@ -47,24 +45,19 @@ public IIRFilter(int order) throws IllegalArgumentException {
      * @throws IllegalArgumentException if {@code aCoeffs} or {@code bCoeffs} is
      * not of size {@code order}, or if {@code aCoeffs[0]} is 0.0
      */
-    public void setCoeffs(double[] aCoeffs, double[] bCoeffs)
-        throws IllegalArgumentException {
+    public void setCoeffs(double[] aCoeffs, double[] bCoeffs) throws IllegalArgumentException {
         if (aCoeffs.length != order) {
             throw new IllegalArgumentException(
-                "aCoeffs must be of size " + order + ", got " + aCoeffs.length
-            );
+                "aCoeffs must be of size " + order + ", got " + aCoeffs.length);
         }
 
         if (aCoeffs[0] == 0.0) {
-            throw new IllegalArgumentException(
-                "aCoeffs.get(0) must not be zero"
-            );
+            throw new IllegalArgumentException("aCoeffs.get(0) must not be zero");
         }
 
         if (bCoeffs.length != order) {
             throw new IllegalArgumentException(
-                "bCoeffs must be of size " + order + ", got " + bCoeffs.length
-            );
+                "bCoeffs must be of size " + order + ", got " + bCoeffs.length);
         }
 
         for (int i = 0; i <= order; i++) {
@@ -84,8 +77,7 @@ public double process(double sample) {
 
         // Process
         for (int i = 1; i <= order; i++) {
-            result +=
-                (coeffsB[i] * historyX[i - 1] - coeffsA[i] * historyY[i - 1]);
+            result += (coeffsB[i] * historyX[i - 1] - coeffsA[i] * historyY[i - 1]);
         }
         result = (result + coeffsB[0] * sample) / coeffsA[0];
 

@@ -1,4 +1,5 @@
-/** Author : Siddhant Swarup Mallick
+/**
+ * Author : Siddhant Swarup Mallick
  * Github : https://github.com/siddhant2002
  */
 
@@ -15,13 +16,12 @@ public class AllPathsFromSourceToTarget {
     private int v;
 
     // To store the paths from source to destination
-    static List<List<Integer>> nm=new ArrayList<>();
+    static List<List<Integer>> nm = new ArrayList<>();
     // adjacency list
     private ArrayList<Integer>[] adjList;
 
     // Constructor
-    public AllPathsFromSourceToTarget(int vertices)
-    {
+    public AllPathsFromSourceToTarget(int vertices) {
 
         // initialise vertex count
         this.v = vertices;
@@ -31,8 +31,7 @@ public AllPathsFromSourceToTarget(int vertices)
     }
 
     // utility method to initialise adjacency list
-    private void initAdjList()
-    {
+    private void initAdjList() {
         adjList = new ArrayList[v];
 
         for (int i = 0; i < v; i++) {
@@ -41,15 +40,12 @@ private void initAdjList()
     }
 
     // add edge from u to v
-    public void addEdge(int u, int v)
-    {
+    public void addEdge(int u, int v) {
         // Add v to u's list.
         adjList[u].add(v);
     }
 
-
-    public void storeAllPaths(int s, int d)
-    {
+    public void storeAllPaths(int s, int d) {
         boolean[] isVisited = new boolean[v];
         ArrayList<Integer> pathList = new ArrayList<>();
 
@@ -61,9 +57,9 @@ public void storeAllPaths(int s, int d)
 
     // A recursive function to print all paths from 'u' to 'd'.
     // isVisited[] keeps track of vertices in current path.
-    // localPathList<> stores actual vertices in the current path 
-    private void storeAllPathsUtil(Integer u, Integer d, boolean[] isVisited, List<Integer> localPathList)
-    {
+    // localPathList<> stores actual vertices in the current path
+    private void storeAllPathsUtil(
+        Integer u, Integer d, boolean[] isVisited, List<Integer> localPathList) {
 
         if (u.equals(d)) {
             nm.add(new ArrayList<>(localPathList));
@@ -74,7 +70,7 @@ private void storeAllPathsUtil(Integer u, Integer d, boolean[] isVisited, List<I
         isVisited[u] = true;
 
         // Recursion for all the vertices adjacent to current vertex
-        
+
         for (Integer i : adjList[u]) {
             if (!isVisited[i]) {
                 // store current node in path[]
@@ -91,12 +87,11 @@ private void storeAllPathsUtil(Integer u, Integer d, boolean[] isVisited, List<I
     }
 
     // Driver program
-    public static List<List<Integer>> allPathsFromSourceToTarget(int vertices, int[][] a, int source, int destination)
-    {
+    public static List<List<Integer>> allPathsFromSourceToTarget(
+        int vertices, int[][] a, int source, int destination) {
         // Create a sample graph
         AllPathsFromSourceToTarget g = new AllPathsFromSourceToTarget(vertices);
-        for(int i=0 ; i<a.length ; i++)
-        {
+        for (int i = 0; i < a.length; i++) {
             g.addEdge(a[i][0], a[i][1]);
             // edges are added
         }

@@ -22,7 +22,7 @@ public static List<TreeSet<Integer>> combination(int n, int k) {
         length = k;
         Integer[] arr = new Integer[n];
         for (int i = 1; i <= n; i++) {
-            arr[i-1] = i;
+            arr[i - 1] = i;
         }
         return Combination.combination(arr, length);
     }

@@ -38,11 +38,7 @@ public static <T> List<TreeSet<T>> combination(T[] arr, int n) {
      * @param <T> the type of elements in the array.
      */
     private static <T> void backtracking(
-        T[] arr,
-        int index,
-        TreeSet<T> currSet,
-        List<TreeSet<T>> result
-    ) {
+        T[] arr, int index, TreeSet<T> currSet, List<TreeSet<T>> result) {
         if (index + length - currSet.size() > arr.length) return;
         if (length - 1 == currSet.size()) {
             for (int i = index; i < arr.length; i++) {

@@ -38,13 +38,7 @@ public static void putPixel(int[][] image, int x, int y, int newColor) {
      * @param newColor The new color which to be filled in the image
      * @param oldColor The old color which is to be replaced in the image
      */
-    public static void floodFill(
-        int[][] image,
-        int x,
-        int y,
-        int newColor,
-        int oldColor
-    ) {
+    public static void floodFill(int[][] image, int x, int y, int newColor, int oldColor) {
         if (x < 0 || x >= image.length) return;
         if (y < 0 || y >= image[x].length) return;
         if (getPixel(image, x, y) != oldColor) return;

@@ -4,9 +4,10 @@
 
 /*
     * Problem Statement: -
-
-    Given a N*N board with the Knight placed on the first block of an empty board. Moving according to the rules of
-    chess knight must visit each square exactly once. Print the order of each cell in which they are visited.
+
+    Given a N*N board with the Knight placed on the first block of an empty board. Moving according
+   to the rules of chess knight must visit each square exactly once. Print the order of each cell in
+   which they are visited.
 
     Example: -
 
@@ -27,14 +28,14 @@ public class KnightsTour {
 
     private static final int base = 12;
     private static final int[][] moves = {
-        { 1, -2 },
-        { 2, -1 },
-        { 2, 1 },
-        { 1, 2 },
-        { -1, 2 },
-        { -2, 1 },
-        { -2, -1 },
-        { -1, -2 },
+        {1, -2},
+        {2, -1},
+        {2, 1},
+        {1, 2},
+        {-1, 2},
+        {-2, 1},
+        {-2, -1},
+        {-1, -2},
     }; // Possible moves by knight on chess
     private static int[][] grid; // chess grid
     private static int total; // total squares in chess
@@ -75,23 +76,17 @@ private static boolean solve(int row, int column, int count) {
             return false;
         }
 
-        Collections.sort(
-            neighbor,
-            new Comparator<int[]>() {
-                public int compare(int[] a, int[] b) {
-                    return a[2] - b[2];
-                }
+        Collections.sort(neighbor, new Comparator<int[]>() {
+            public int compare(int[] a, int[] b) {
+                return a[2] - b[2];
             }
-        );
+        });
 
         for (int[] nb : neighbor) {
             row = nb[0];
             column = nb[1];
             grid[row][column] = count;
-            if (
-                !orphanDetected(count, row, column) &&
-                solve(row, column, count + 1)
-            ) {
+            if (!orphanDetected(count, row, column) && solve(row, column, count + 1)) {
                 return true;
             }
             grid[row][column] = 0;
@@ -109,7 +104,7 @@ private static List<int[]> neighbors(int row, int column) {
             int y = m[1];
             if (grid[row + y][column + x] == 0) {
                 int num = countNeighbors(row + y, column + x);
-                neighbour.add(new int[] { row + y, column + x, num });
+                neighbour.add(new int[] {row + y, column + x, num});
             }
         }
         return neighbour;

@@ -51,9 +51,7 @@ public static void mazeRecursion() {
         setWay2(map2, 1, 1);
 
         // Print out the new map1, with the ball footprint
-        System.out.println(
-            "After the ball goes through the map1，show the current map1 condition"
-        );
+        System.out.println("After the ball goes through the map1，show the current map1 condition");
         for (int i = 0; i < 8; i++) {
             for (int j = 0; j < 7; j++) {
                 System.out.print(map[i][j] + " ");
@@ -62,9 +60,7 @@ public static void mazeRecursion() {
         }
 
         // Print out the new map2, with the ball footprint
-        System.out.println(
-            "After the ball goes through the map2，show the current map2 condition"
-        );
+        System.out.println("After the ball goes through the map2，show the current map2 condition");
         for (int i = 0; i < 8; i++) {
             for (int j = 0; j < 7; j++) {
                 System.out.print(map2[i][j] + " ");
@@ -85,7 +81,7 @@ public static void mazeRecursion() {
      * means the ball has gone through the path but this path is dead end
      * 5. We will need strategy for the ball to pass through the maze for example:
      * Down -> Right -> Up -> Left, if the path doesn't work, then backtrack
-     * 
+     *
      * @author OngLipWei
      * @version Jun 23, 2021 11:36:14 AM
      * @param map The maze
@@ -99,7 +95,8 @@ public static boolean setWay(int[][] map, int i, int j) {
         }
         if (map[i][j] == 0) { // if the ball haven't gone through this point
             // then the ball follows the move strategy : down -> right -> up -> left
-            map[i][j] = 2; // we assume that this path is feasible first, set the current point to 2 first。
+            map[i][j] = 2; // we assume that this path is feasible first, set the current point to 2
+                           // first。
             if (setWay(map, i + 1, j)) { // go down
                 return true;
             } else if (setWay(map, i, j + 1)) { // go right
@@ -129,7 +126,8 @@ public static boolean setWay2(int[][] map, int i, int j) {
         }
         if (map[i][j] == 0) { // if the ball haven't gone through this point
             // then the ball follows the move strategy : up->right->down->left
-            map[i][j] = 2; // we assume that this path is feasible first, set the current point to 2 first。
+            map[i][j] = 2; // we assume that this path is feasible first, set the current point to 2
+                           // first。
             if (setWay2(map, i - 1, j)) { // go up
                 return true;
             } else if (setWay2(map, i, j + 1)) { // go right

@@ -47,14 +47,8 @@ public static void placeQueens(final int queens) {
         List<List<String>> arrangements = new ArrayList<List<String>>();
         getSolution(queens, arrangements, new int[queens], 0);
         if (arrangements.isEmpty()) {
-            System.out.println(
-                "There is no way to place " +
-                queens +
-                " queens on board of size " +
-                queens +
-                "x" +
-                queens
-            );
+            System.out.println("There is no way to place " + queens + " queens on board of size "
+                + queens + "x" + queens);
         } else {
             System.out.println("Arrangement for placing " + queens + " queens");
         }
@@ -73,11 +67,7 @@ public static void placeQueens(final int queens) {
      * @param columnIndex: This is the column in which queen is being placed
      */
     private static void getSolution(
-        int boardSize,
-        List<List<String>> solutions,
-        int[] columns,
-        int columnIndex
-    ) {
+        int boardSize, List<List<String>> solutions, int[] columns, int columnIndex) {
         if (columnIndex == boardSize) {
             // this means that all queens have been placed
             List<String> sol = new ArrayList<String>();
@@ -96,7 +86,8 @@ private static void getSolution(
         for (int rowIndex = 0; rowIndex < boardSize; rowIndex++) {
             columns[columnIndex] = rowIndex;
             if (isPlacedCorrectly(columns, rowIndex, columnIndex)) {
-                // If queen is placed successfully at rowIndex in column=columnIndex then try placing queen in next column
+                // If queen is placed successfully at rowIndex in column=columnIndex then try
+                // placing queen in next column
                 getSolution(boardSize, solutions, columns, columnIndex + 1);
             }
         }
@@ -111,11 +102,7 @@ private static void getSolution(
      * @param columnIndex: column in which queen is being placed
      * @return true: if queen can be placed safely false: otherwise
      */
-    private static boolean isPlacedCorrectly(
-        int[] columns,
-        int rowIndex,
-        int columnIndex
-    ) {
+    private static boolean isPlacedCorrectly(int[] columns, int rowIndex, int columnIndex) {
         for (int i = 0; i < columnIndex; i++) {
             int diff = Math.abs(columns[i] - rowIndex);
             if (diff == 0 || columnIndex - i == diff) {