Added Spam message solution written during leetcode contest

Author: aishsingh

ReportSpamMessage/solution.cpp

@@ -0,0 +1,39 @@
+#include <unordered_map>
+
+class Solution {
+public:
+    bool reportSpam(vector<string>& message, vector<string>& bannedWords) 
+    {
+        // use hashmap to efficiently keep count of each word in both lists
+        unordered_map<string, int> hashmap;
+        for (const auto& word : message)
+        {
+            hashmap[word]++;
+        }
+
+        // keep banned words in a set so there are no duplicates
+        set<string> bannedSet;
+        for (const auto& word : bannedWords)
+            bannedSet.insert(word);
+
+        // check the count of the hashmap words against the banned words
+        int totalBannedWordsFound = 0;
+        for (const auto& word : bannedSet)
+        {
+            int bannedWordCount = hashmap[word];
+            if (bannedWordCount > 0)
+            {
+                totalBannedWordsFound += bannedWordCount;
+
+                if (totalBannedWordsFound >= 2)
+                {
+                    // the message meets the critera to be considered spam
+                    return true;
+                }
+            }
+        }
+        
+        // if we reached here then then there were not enough baned words to be considered spam
+        return false;
+    }
+};