Create count-items-matching-a-rule.cpp

Author: kamyu104

C++/count-items-matching-a-rule.cpp

@@ -0,0 +1,16 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    int countMatches(vector<vector<string>>& items, string ruleKey, string ruleValue) {
+        static const unordered_map<string, int> rule = {{"type", 0}, {"color", 1}, {"name", 2}};
+        int result = 0;
+        for (const auto& item : items) {
+            if (item[rule.at(ruleKey)] == ruleValue) {
+                ++result;
+            }
+        }
+        return result;
+    }
+};