Solved roman-numerals

CMakeLists.txt

@@ -23,4 +23,5 @@ enable_testing()
 include(GoogleTest)
 
 add_subdirectory( two-sum )
-add_subdirectory( longest-substring-without-repeating-characters )
+add_subdirectory( longest-substring-without-repeating-characters )
+add_subdirectory( roman-numerals )

roman-numerals/CMakeLists.txt

@@ -0,0 +1,25 @@
+cmake_minimum_required(VERSION 3.14)
+project(roman_numerals)
+
+# GoogleTest requires at least C++14
+set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+enable_testing()
+
+add_executable(
+  roman_numerals_runner
+  runner.cpp
+)
+
+add_executable(
+  roman_numerals_tests
+  tests.cpp
+)
+target_link_libraries(
+  roman_numerals_tests
+  GTest::gtest_main
+)
+include_directories(${gtest_SOURCE_DIR}/include ${COMMON_INCLUDES})
+
+gtest_discover_tests(roman_numerals_tests)

roman-numerals/runner.cpp

@@ -0,0 +1,13 @@
+#include <iostream>
+#include <string>
+
+#include "solution.hpp"
+
+int main()
+{
+    const std::string input("XCXLV");
+    Solution s;
+    std::cout << "\"" << input << "\": " << s.romanToInt(input) << std::endl;
+
+    return 1;
+}

roman-numerals/solution.hpp

@@ -0,0 +1,42 @@
+#pragma once
+
+#include <string>
+
+class Solution {
+public:
+    int romanToInt(const std::string& s) 
+    {
+        int result = 0;
+        char prev = 'z';
+        for (const char c : s)
+        {
+            switch (c)
+            {
+                case 'I':
+                    result += 1;
+                    break;
+                case 'V':
+                    result += prev == 'I' ? 3 : 5;
+                    break;
+                case 'X':
+                    result += prev == 'I' ? 8 : 10;
+                    break;
+                case 'L':
+                    result += prev == 'X' ? 30 : 50;
+                    break;
+                case 'C':
+                    result += prev == 'X' ? 80 : 100;
+                    break;
+                case 'D':
+                    result += prev == 'C' ? 300 :500;
+                    break;
+                case 'M':
+                    result += prev == 'C' ? 800 :1000;
+                    break;
+            }
+            prev = c;
+        }
+
+        return result;
+    }
+};

roman-numerals/tests.cpp

@@ -0,0 +1,53 @@
+#include <gtest/gtest.h>
+
+#include <string>
+#include <utility>
+
+#include "solution.hpp"
+
+class RomanNumeralsTest :public ::testing::TestWithParam<std::pair<std::string, int>> {
+protected:
+    Solution solution;
+};
+
+TEST_P(RomanNumeralsTest, CheckSolution) {
+    std::string input = std::get<0>(GetParam());
+    int expected = std::get<1>(GetParam());
+
+    int actual = solution.romanToInt(input);
+
+    EXPECT_EQ(expected, actual);
+}
+
+auto values = ::testing::Values(
+                std::make_pair("I", 1),
+                std::make_pair("II", 2),
+                std::make_pair("III", 3),
+                std::make_pair("V", 5),
+                std::make_pair("VI", 6),
+                std::make_pair("IV", 4),
+                std::make_pair("VII", 7),
+                std::make_pair("X", 10),
+                std::make_pair("XXVII", 27),
+                std::make_pair("XXI", 21),
+                std::make_pair("IX", 9),
+                std::make_pair("XXIX", 29),
+                std::make_pair("L", 50),
+                std::make_pair("LI", 51),
+                std::make_pair("XLVI", 46),
+                std::make_pair("C", 100),
+                std::make_pair("CXX", 120),
+                std::make_pair("XCXLV", 135),
+                std::make_pair("CXC", 190),
+                std::make_pair("D", 500),
+                std::make_pair("DC", 600),
+                std::make_pair("CDLXIII", 463),
+                std::make_pair("M", 1000),
+                std::make_pair("MCMXCIX", 1999)
+                );
+
+INSTANTIATE_TEST_CASE_P(
+        RomanNumeralsTests,
+        RomanNumeralsTest,
+        values
+        );