add tennis7 in cpp

cpp/CMakeLists.txt

@@ -44,4 +44,10 @@ add_executable(tennis6_google_test
         tennis6.cc
         gtest_all.cpp)
 target_link_libraries(tennis6_google_test GTest::gtest_main)
-gtest_discover_tests(tennis6_google_test)
+gtest_discover_tests(tennis6_google_test)
+
+add_executable(tennis7_google_test
+        tennis7.cc
+        gtest_all.cpp)
+target_link_libraries(tennis7_google_test GTest::gtest_main)
+gtest_discover_tests(tennis7_google_test)

cpp/tennis7.cc

@@ -0,0 +1,73 @@
+#include <string>
+
+std::string tennis_score(int player1Score, int player2Score)
+{
+    std::string result = "";
+    std::string player1Name = "player1";
+    std::string player2Name = "player2";
+
+    if (player1Score == player2Score)
+    {
+        // tie score
+        switch (player1Score)
+        {
+            case 0: result += "Love-All"; break;
+            case 1: result += "Fifteen-All"; break;
+            case 2: result += "Thirty-All"; break;
+            default: result += "Deuce"; break;
+        }
+    }
+    else if (player1Score >= 4 || player2Score >= 4)
+    {
+        // end-game score
+        if (player1Score - player2Score == 1)
+        {
+            result += "Advantage " + player1Name;
+        }
+        else if (player1Score - player2Score == -1)
+        {
+            result += "Advantage " + player2Name;
+        }
+        else if (player1Score - player2Score >= 2)
+        {
+            result += "Win for " + player1Name;
+        }
+        else
+        {
+            result += "Win for " + player2Name;
+        }
+    } else {
+        // regular score
+        switch (player1Score) {
+            case 0:
+                result += "Love";
+            break;
+            case 1:
+                result += "Fifteen";
+            break;
+            case 2:
+                result += "Thirty";
+            break;
+            default:
+                result += "Forty";
+            break;
+        }
+        result += "-";
+        switch (player2Score) {
+            case 0:
+                result += "Love";
+            break;
+            case 1:
+                result += "Fifteen";
+            break;
+            case 2:
+                result += "Thirty";
+            break;
+            default:
+                result += "Forty";
+            break;
+        }
+    }
+
+    return result;
+}