Added InsertionSort in Classic Java Algorithm

Author: ReactorboY

classical_algorithms/java/InsertionSort.java

@@ -0,0 +1,45 @@
+import java.util.Scanner;
+public class InsertionSort
+{
+    private static void insertionSort(int array[], int size){
+        for (int i = 1; i < size; i++){
+            int key = array[i];
+            int j = i -1;
+            while ( j >= 0 && array[j] > key) {
+                array[j+1] = array[j];
+                j = j - 1;
+            }
+            array[j+1] = key;
+        }
+    }
+    
+    private static void printArray(int array[]) {
+        for(int i = 0; i < array.length;i++) {
+            System.out.print(array[i] + " ");
+        }
+        System.out.println();
+    }
+    
+	public static void main(String[] args) {
+	    Scanner scan = new Scanner(System.in);
+	    try {
+	        int i,n;
+	        System.out.println("How many elements do you want in the array?");
+            n=scan.nextInt();
+            int a[]= new int[n];
+            System.out.println("Enter the array elements one by one");
+
+            for(i=0;i<n;i++)
+            {
+                a[i]=scan.nextInt();
+            }
+            System.out.println("Array before sorting is:");
+            printArray(a);
+            System.out.println("Array before sorting is:");
+            insertionSort(a, a.length);
+            printArray(a);
+	        
+	    } catch(Exception e) {e.printStackTrace();}
+        scan.close();
+	}
+}