s0013

include/s0013_roman_to_integer.hpp

@@ -0,0 +1,14 @@
+#ifndef S0013_ROMAN_TO_INTEGER
+#define S0013_ROMAN_TO_INTEGER
+
+#include <string>
+#include <unordered_map>
+
+using namespace std;
+
+class Solution {
+ public:
+  int romanToInt(string s);
+};
+
+#endif

src/s0013_roman_to_integer.cpp

@@ -0,0 +1,27 @@
+#include "s0013_roman_to_integer.hpp"
+
+int Solution::romanToInt(string s) {
+  unordered_map<string, int> map;
+  map["I"] = 1;
+  map["V"] = 5;
+  map["X"] = 10;
+  map["L"] = 50;
+  map["C"] = 100;
+  map["D"] = 500;
+  map["M"] = 1000;
+
+  int val{0};
+  int len = s.length();
+  for (int i{0}; i < len; i++) {
+    if (i == len - 1) {
+      val += map.at(s.substr(i, 1));
+    } else {
+      if (map.at(s.substr(i, 1)) < map.at(s.substr(i + 1, 1))) {
+        val -= map.at(s.substr(i, 1));
+      } else {
+        val += map.at(s.substr(i, 1));
+      }
+    }
+  }
+  return val;
+}

tests/s0013_roman_to_integer.cpp

@@ -0,0 +1,24 @@
+#include "s0013_roman_to_integer.hpp"
+
+#include <gtest/gtest.h>
+
+TEST(Problem13, Case1) {
+  string i("III");
+  int o{3};
+  Solution solution;
+  EXPECT_EQ(solution.romanToInt(i), o);
+}
+
+TEST(Problem13, Case2) {
+  string i("LVIII");
+  int o{58};
+  Solution solution;
+  EXPECT_EQ(solution.romanToInt(i), o);
+}
+
+TEST(Problem13, Case3) {
+  string i("MCMXCIV");
+  int o{1994};
+  Solution solution;
+  EXPECT_EQ(solution.romanToInt(i), o);
+}