Create to-lower-case.cpp

Author: kamyu104

C++/to-lower-case.cpp

@@ -0,0 +1,17 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    string toLowerCase(string str) {
+        string result;
+        for (const auto c : str) {
+            if ('A' <= c && c <= 'Z') {
+                result.push_back('a' + c - 'A');
+            } else {
+                result.push_back(c);
+            }
+        }
+        return result;
+    }
+};