added intersectionOfTwoArrays

README.md

@@ -8,6 +8,7 @@ LeetCode
 
 | # | Title | Solution | Difficulty |
 |---| ----- | -------- | ---------- |
+|349|[Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays/) | [C++](./algorithms/cpp/intersectionOfTwoArrays/intersectionOfTwoArrays.cpp)|Easy|
 |347|[Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/) | [C++](./algorithms/cpp/topKFrequentElements/topKFrequentElements.cpp)|Medium|
 |345|[Reverse Vowels of a String](https://leetcode.com/problems/reverse-vowels-of-a-string/) | [C++](./algorithms/cpp/reverseVowelsOfAString/reverseVowelsOfAString.cpp)|Easy|
 |337|[House Robber III](https://leetcode.com/problems/house-robber-iii/) | [C++](./algorithms/cpp/houseRobber/houseRobberIII.cpp)|Medium|

algorithms/cpp/intersectionOfTwoArrays/intersectionOfTwoArrays.cpp

@@ -0,0 +1,31 @@
+// Source : https://leetcode.com/problems/intersection-of-two-arrays/
+// Author : Calinescu Valentin
+// Date   : 2016-05-20
+
+/*************************************************************************************** 
+ *
+ * Given two arrays, write a function to compute their intersection.
+ * 
+ * Example:
+ * Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2].
+ * 
+ * Note:
+ * Each element in the result must be unique.
+ * The result can be in any order.
+ * 
+ ***************************************************************************************/
+class Solution {
+public:
+    set <int> inter1, inter2;//we use sets so as to avoid duplicates
+    vector <int> solution;
+    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
+        for(int i = 0; i < nums1.size(); i++)
+            inter1.insert(nums1[i]);//get all of the unique elements in nums1 sorted
+        for(int i = 0; i < nums2.size(); i++)
+            if(inter1.find(nums2[i]) != inter1.end())//search nums1 in O(logN)
+                inter2.insert(nums2[i]);//populate the intersection set
+        for(set<int>::iterator it = inter2.begin(); it != inter2.end(); ++it)
+            solution.push_back(*it);//copy the set into a vector
+        return solution;
+    }
+};