Add Spiral and SwapElements class into arrays package.

arrays/Spiral.java

@@ -0,0 +1,95 @@
+package arrays;
+
+//it returns a two-dimensional array representing a table with sizes of the given parameters
+//a table contains numbers from 1 up to number received by multiplying number of rows and columns
+//numbers fill the table clockwise from the top-level corner in a spiral manner
+
+public class Spiral {
+    static int[][] spiral(int rows, int columns) {
+        int row = 0;
+        int col = 0;
+
+        int boundary = columns - 1;
+        int verticalBoundary = rows - 1;
+        int horizontalBoundary = columns - 1;
+
+        //determine movement r = right...
+        char move = 'r';
+
+        // switching between horizontal and vertical rotations
+        char shift = 'v';
+
+        //Creating array
+        int[][] matrix = new int[rows][columns];
+
+        // One column case
+        if(columns == 1) {
+            for (int i = 1; i < rows * columns + 1; i++) {
+                matrix[row][col] = i;
+                row++;
+            }
+            return matrix;
+        }
+
+        for (int i = 1; i < rows * columns + 1; i++) {
+            matrix [row][col] = i;
+
+            //determining the cell's next index
+            switch (move) {
+                // go right
+                case 'r':
+                    col += 1;
+                    break;
+                // go left
+                case 'l':
+                    col -= 1;
+                    break;
+                // go up
+                case 'u':
+                    row -= 1;
+                    break;
+                // go down
+                case 'd':
+                    row += 1;
+                    break;
+            }
+            //check if a boundary has been reached
+            if(boundary == i){
+                switch (shift) {
+                    case 'v':
+                        if (boundary == i){
+                            boundary += verticalBoundary;
+                            verticalBoundary -= 1;
+                            shift = 'h';
+                        }
+                    case 'h':
+                        if (boundary == i){
+                            boundary += horizontalBoundary;
+                            horizontalBoundary -= 1;
+                            shift = 'v';
+                        }
+                }
+                //change direction
+                switch (move) {
+                    // go right
+                    case 'r':
+                        move = 'd';
+                        break;
+                    // go left
+                    case 'l':
+                        move = 'u';
+                        break;
+                    // go up
+                    case 'u':
+                        move =  'r';
+                        break;
+                    // go down
+                    case 'd':
+                        move = 'l';
+                        break;
+                }
+            }
+        }
+        return matrix;
+    }
+}

arrays/SwapElements.java

@@ -0,0 +1,30 @@
+package arrays;
+
+public class SwapElements {
+
+// it shifts all the elements in given array to the right by 1 position
+    static void cycleSwap(int[] array) {
+        if(array.length == 0){
+            return;
+        }
+        int temp = array[array.length - 1];
+        for(int i = array.length - 2; i > -1; i--){
+            array[i + 1] = array[i];
+        }
+        array[0] = temp;
+    }
+
+//    it shifts all the elements in the given array to the right direction by specified numbers of postion
+    static void cycleSwap(int[] array, int shift) {
+        if(array.length == 0){
+            return;
+        }
+        for(int j = 1; j <= shift; j++){
+            int temp = array[array.length - 1];
+            for(int i = array.length - 2; i > -1; i--){
+                array[i + 1] = array[i];
+            }
+            array[0] = temp;
+        }
+    }
+}