Create IntersectionOfArrays.java

IntersectionOfArrays.java

@@ -0,0 +1,45 @@
+import java.util.* ;
+import java.io.*;
+public class IntersectionOfArrays
+{
+    public static ArrayList<Integer> findArrayIntersection(ArrayList<Integer> arr1, int n, ArrayList<Integer> arr2, int m)
+    {
+
+        ArrayList<Integer>list = new ArrayList<>();
+        //initializing pointers to 0
+        int i = 0;
+        int j = 0;
+        while(i < n && j < m){
+            if(arr1.get(i).equals(arr2.get(j)))//use equals to check same value bcz if u use == it checks object.
+            {
+                list.add(arr1.get(i));
+                i++;
+                j++;
+            }
+            else if(arr1.get(i) < arr2.get(j))//since array is sorted so increment first array pointer if value is less than value in 2nd array
+            {
+                i++;
+            }
+            else{
+                j++;
+            }
+        }
+        if(list.size()== 0)
+            list.add(-1);
+
+        return list;
+    }
+
+    public static void main(String[] args) {
+
+        ArrayList<Integer> ans = new ArrayList<>();
+
+        ArrayList<Integer>l1 = new ArrayList<>(List.of(1,2,2,2,3,4));
+        ArrayList<Integer>l2 = new ArrayList<>(List.of(2,2,3,3));
+//        ArrayList<Integer>l1 = new ArrayList<>(List.of(3,4));
+//        ArrayList<Integer>l2 = new ArrayList<>(List.of(2,2));
+        ans = findArrayIntersection(l1,l1.size(),l2,l2.size());
+
+        System.out.println(ans);
+    }
+}