Create find-common-characters.cpp

Author: kamyu104

C++/find-common-characters.cpp

@@ -0,0 +1,25 @@
+// Time:  O(n * l)
+// Space: O(1)
+
+class Solution {
+public:
+    vector<string> commonChars(vector<string>& A) {
+        vector<int> count(26, numeric_limits<int>::max());
+        vector<string> result;
+        for (const auto& a : A) {
+            vector<int> tmp_count(count.size());
+            for (const auto& c : a) {
+                ++tmp_count[c - 'a'];
+            }
+            for (int i = 0; i < count.size(); ++i) {
+                count[i] = min(count[i], tmp_count[i]);
+            }
+        }
+        for (int i = 0; i < count.size(); ++i) {
+            for (auto j = 0; j < count[i]; ++j) {
+                result.emplace_back(1, i + 'a');
+            }
+        }
+        return result;
+    }
+};