feat: add cpp solutions to leetcode problem No.12,No.13

Author: maolonglong

solution/0000-0099/0012.Integer to Roman/README.md

@@ -119,6 +119,26 @@ class Solution {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    string intToRoman(int num) {
+        vector<int> nums{1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};
+        vector<string> romans{"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};
+        string ans;
+        for (int i = 0; i < nums.size(); ++i) {
+            while (num >= nums[i]) {
+                num -= nums[i];
+                ans.append(romans[i]);
+            }
+        }
+        return ans;
+    }
+};
+```
+
 ### **...**
 
 ```

solution/0000-0099/0012.Integer to Roman/README_EN.md

@@ -111,6 +111,26 @@ class Solution {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    string intToRoman(int num) {
+        vector<int> nums{1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};
+        vector<string> romans{"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};
+        string ans;
+        for (int i = 0; i < nums.size(); ++i) {
+            while (num >= nums[i]) {
+                num -= nums[i];
+                ans.append(romans[i]);
+            }
+        }
+        return ans;
+    }
+};
+```
+
 ### **...**
 
 ```

solution/0000-0099/0012.Integer to Roman/Solution.cpp

@@ -0,0 +1,15 @@
+class Solution {
+public:
+    string intToRoman(int num) {
+        vector<int> nums{1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};
+        vector<string> romans{"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};
+        string ans;
+        for (int i = 0; i < nums.size(); ++i) {
+            while (num >= nums[i]) {
+                num -= nums[i];
+                ans.append(romans[i]);
+            }
+        }
+        return ans;
+    }
+};

solution/0000-0099/0013.Roman to Integer/README.md

@@ -154,6 +154,33 @@ class Solution {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+   public:
+    int romanToInt(string s) {
+        unordered_map<char, int> nums{
+            {'I', 1},
+            {'V', 5},
+            {'X', 10},
+            {'L', 50},
+            {'C', 100},
+            {'D', 500},
+            {'M', 1000},
+        };
+        int ans = 0;
+        for (int i = 0; i < s.size() - 1; ++i) {
+            if (nums[s[i]] < nums[s[i + 1]])
+                ans -= nums[s[i]];
+            else
+                ans += nums[s[i]];
+        }
+        return ans + nums[s.back()];
+    }
+};
+```
+
 ### **...**
 
 ```

solution/0000-0099/0013.Roman to Integer/README_EN.md

@@ -205,6 +205,33 @@ class Solution {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+   public:
+    int romanToInt(string s) {
+        unordered_map<char, int> nums{
+            {'I', 1},
+            {'V', 5},
+            {'X', 10},
+            {'L', 50},
+            {'C', 100},
+            {'D', 500},
+            {'M', 1000},
+        };
+        int ans = 0;
+        for (int i = 0; i < s.size() - 1; ++i) {
+            if (nums[s[i]] < nums[s[i + 1]])
+                ans -= nums[s[i]];
+            else
+                ans += nums[s[i]];
+        }
+        return ans + nums[s.back()];
+    }
+};
+```
+
 ### **...**
 
 ```

solution/0000-0099/0013.Roman to Integer/Solution.cpp

@@ -0,0 +1,22 @@
+class Solution {
+   public:
+    int romanToInt(string s) {
+        unordered_map<char, int> nums{
+            {'I', 1},
+            {'V', 5},
+            {'X', 10},
+            {'L', 50},
+            {'C', 100},
+            {'D', 500},
+            {'M', 1000},
+        };
+        int ans = 0;
+        for (int i = 0; i < s.size() - 1; ++i) {
+            if (nums[s[i]] < nums[s[i + 1]])
+                ans -= nums[s[i]];
+            else
+                ans += nums[s[i]];
+        }
+        return ans + nums[s.back()];
+    }
+};