Added code for wave form array

Java/WaveArr1.java

@@ -0,0 +1,37 @@
+import java.util.*;
+public class WaveArr1
+{
+    //method to swap two numbers.
+    static void swap(int arr[], int a, int b)
+    {
+        int temp = arr[a];
+        arr[a] = arr[b];
+        arr[b] = temp;
+    }
+
+    static void sort1(int a[], int n)
+    {
+    	for(int i = 0; i < n-1; i+=2){
+            //swap odd and even positions
+            if(i > 0 && a[i - 1] > a[i])
+            	swap(a, i, i-1);
+            if(i < n-1 && a[i + 1] > a[i])
+            	swap(a, i, i+1);
+    	}
+    }
+
+    public static void main(String args[])
+    {
+    	Scanner sc = new Scanner(System.in);
+    	System.out.println("Enter length of array:");
+    	int n = sc.nextInt();
+    	int[] a = new int[n];
+        System.out.println("Enter array elements:");
+        for(int i = 0; i<n; i++)
+        	a[i] = sc.nextInt();
+        sort1(a, n);
+        for (int i : a)
+            System.out.print(i + " ");
+        sc.close();
+    }
+}