Merge pull request #602 from Spidy-Coder/Spidy-Coder-patch-1

Adding Union of two arrays.cpp

08. Hashing/Union of two arrays.cpp

@@ -0,0 +1,21 @@
+//Problem statement URL:- https://practice.geeksforgeeks.org/problems/union-of-two-arrays3538/1/?track=DSASP-Hashing&batchId=154
+//Hashing approach
+
+class Solution{
+    public:
+    //Function to return the count of number of elements in union of two arrays.
+    int doUnion(int a[], int n, int b[], int m)  {
+        // Efficient Approach:-step-wise
+
+        // 1. Create a set, and insert a[] elements which will be distinct in set
+        unordered_set<int> s(a,a+n); 
+
+        // 2. Insert b[] elements in the same set
+        for(int i=0;i<m;i++){
+            s.insert(b[i]); //disinct elements will only be inserted.
+        }
+
+        // 3. size of our created set s
+        return s.size();
+    }
+};