feat: add cpp solution to lcof2 problem: NO.046 (doocs#567)

Co-authored-by: willrlzhang <willrlzhang@tencent.com>
Co-authored-by: 陈劭珑 <382084620@qq.com>

Author: 3 people

lcof2/剑指 Offer II 046. 二叉树的右侧视图/README.md

@@ -67,6 +67,55 @@
 
 ```
 
+### **C++**
+
+```cpp
+class Solution
+{
+public:
+    vector<int> rightSideView ( TreeNode* root )
+    {
+        vector<int> res;
+
+        if ( !root )
+        {
+            return res;
+        }
+
+        queue<TreeNode* > que;
+        que.push ( root );
+
+        while ( !que.empty() )
+        {
+            int size = que.size();
+
+            for ( int i = 0; i < size; i++ )
+            {
+                TreeNode* ptr = que.front();
+                que.pop();
+
+                if ( i == size - 1 )
+                {
+                    res.push_back ( ptr->val );
+                }
+
+                if ( ptr->left )
+                {
+                    que.push ( ptr->left );
+                }
+
+                if ( ptr-> right )
+                {
+                    que.push ( ptr->right );
+                }
+            }
+        }
+
+        return res;
+    }
+};
+```
+
 ### **...**
 
 ```

lcof2/剑指 Offer II 046. 二叉树的右侧视图/Solution.cpp

@@ -0,0 +1,44 @@
+class Solution
+{
+public:
+    vector<int> rightSideView ( TreeNode* root )
+    {
+        vector<int> res;
+
+        if ( !root )
+        {
+            return res;
+        }
+
+        queue<TreeNode* > que;
+        que.push ( root );
+
+        while ( !que.empty() )
+        {
+            int size = que.size();
+
+            for ( int i = 0; i < size; i++ )
+            {
+                TreeNode* ptr = que.front();
+                que.pop();
+
+                if ( i == size - 1 )
+                {
+                    res.push_back ( ptr->val );
+                }
+
+                if ( ptr->left )
+                {
+                    que.push ( ptr->left );
+                }
+
+                if ( ptr-> right )
+                {
+                    que.push ( ptr->right );
+                }
+            }
+        }
+
+        return res;
+    }
+};