Spiral Pattern

README.md

@@ -190,4 +190,12 @@
 *         * 
 *         * 
 * * * * * * 
-```
+```
+18. Spiral Pattern
+```
+1 2 3 4 5 
+16 17 18 19 6 
+15 24 25 20 7 
+14 23 22 21 8 
+13 12 11 10 9
+```

src/SpiralPattern/Spiral_Pattern.java

@@ -0,0 +1,98 @@
+import java.util.Scanner;  
+
+public class Spiral_Pattern  
+{  
+static void printSpiralPattern(int size)  
+{  
+//create two variables row and col to traverse rows and columns  
+int row = 0, col = 0;  
+int boundary = size - 1;  
+int sizeLeft = size - 1;  
+int flag = 1;  
+//variables r, l, u and d are used to determine the movement  
+// r = right, l = left, d = down, u = upper  
+char move = 'r';  
+//creating a 2D array for matrix  
+int[][] matrix =new int [size][size];  
+for (int i = 1; i < size * size + 1; i++)  
+{  
+    matrix[row][col] = i;  
+//determining the next index  
+switch (move)  
+{  
+//if move = right, go right  
+case 'r':  
+    col += 1;  
+    break;  
+//if move = left, go left  
+case 'l':  
+    col -= 1;  
+    break;  
+//if move = up, go up  
+case 'u':  
+    row -= 1;  
+    break;  
+//if move = down, go down  
+case 'd':  
+    row += 1;  
+    break;  
+}  
+if (i == boundary)  
+    {  
+        //adding left size for the next boundary  
+        boundary = boundary + sizeLeft;  
+        //decreasing the size of left by 1, if 2 rotations have been made  
+        if (flag != 2)  
+        {  
+        flag = 2;  
+        }  
+        else  
+        {  
+        flag = 1;  
+        sizeLeft -= 1;  
+        }  
+        //rotating the movement  
+        switch (move)  
+        {  
+        //if move = right, rotate to down  
+        case 'r':  
+            move = 'd';  
+            break;  
+        // if move = down, rotate to left  
+        case 'd':  
+            move = 'l';  
+            break;  
+        // if move = left, rotate to up  
+        case 'l':  
+            move = 'u';  
+            break;  
+        // if move = up, rotate to right  
+        case 'u':  
+            move = 'r';  
+            break;  
+        }  
+    }  
+    }  
+
+    for (row = 0; row < size; row++)  
+    {  
+        for (col = 0; col < size; col++)  
+            {  
+                int n = matrix[row][col];  
+                if(n < 10)  
+                    System.out.print(n +" ");  
+                else  
+                    System.out.print(n +" ");  
+            }  
+        System.out.println();  
+    }  
+}  
+public static void main(String args[])  
+{  
+Scanner scanner = new Scanner(System.in);
+System.out.println("Enter the size of array: \n");  
+int size = scanner.nextInt();
+System.out.println("Spiral Matrix or Pattern is: \n");  
+printSpiralPattern(size);  
+}  
+}