Substitute Spaces

tests/offer_05.cpp

@@ -0,0 +1,10 @@
+#include "offer_05.hpp"
+
+#include <gtest/gtest.h>
+
+TEST(Offer05, Case1) {
+  string s{"We are happy."};
+  string expected{"We%20are%20happy."};
+  Solution solution;
+  EXPECT_EQ(solution.replaceSpace(s), expected);
+}