Chunel feng/lcof cpp (doocs#335)

* 更新lcof-cpp版本[机器人的运动范围]题解思路

* 更新lcof-cpp版本[从上到下打印二叉树]源码

* Update README.md

* Update Solution.cpp

Co-authored-by: junfeng.fj <junfeng.fj@alibaba-inc.com>
Co-authored-by: Yang Libin <contact@yanglibin.info>

Author: 3 people

lcof/面试题13. 机器人的运动范围/README.md

@@ -173,6 +173,54 @@ func dfs(x, y, m, n, k int, visited [][]bool) int {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    int checksum(int m, int n, int target) {
+        int a = 0;
+        while (m > 0) {
+            a += m % 10;
+            m /= 10;
+        }
+
+        int b = 0;
+        while (n > 0) {
+            b += n % 10;
+            n /= 10;
+        }
+
+        return a + b <= target;
+    }
+
+    int moving(int row, int col, vector<vector<int>>& arr, int i, int j, int target) {
+        int count = 0;
+        if (checksum(i, j, target) 
+            && i>=0 && i < row && j>=0 && j < col
+            && arr[i][j] == 0) {
+            arr[i][j] = 1;
+            count = 1 + moving(row, col, arr, i-1, j, target)
+                    + moving(row, col, arr, i, j-1, target)
+                    + moving(row, col, arr, i+1, j, target)
+                    + moving(row, col, arr, i, j+1, target);
+        }
+
+        return count;
+    }
+
+    int movingCount(int m, int n, int k) {
+        if (m == 0 || n == 0) {
+            return 0;
+        }
+
+        vector<vector<int>> arr(m, vector<int>(n, 0));
+        int cnt = moving(m, n, arr, 0, 0, k);
+        return cnt;
+    }
+};
+```
+
 ### **...**
 
 ```

lcof/面试题13. 机器人的运动范围/Solution.cpp

@@ -0,0 +1,37 @@
+class Solution {
+public:
+    int checksum(int m, int n, int target) {
+        int a = 0;
+        while (m > 0) {
+            a += m % 10;
+            m /= 10;
+        }
+        int b = 0;
+        while (n > 0) {
+            b += n % 10;
+            n /= 10;
+        }
+        return a + b <= target;
+    }
+    int moving(int row, int col, vector<vector<int>>& arr, int i, int j, int target) {
+        int count = 0;
+        if (checksum(i, j, target) 
+            && i>=0 && i < row && j>=0 && j < col
+            && arr[i][j] == 0) {
+            arr[i][j] = 1;
+            count = 1 + moving(row, col, arr, i-1, j, target)
+                    + moving(row, col, arr, i, j-1, target)
+                    + moving(row, col, arr, i+1, j, target)
+                    + moving(row, col, arr, i, j+1, target);
+        }
+        return count;
+    }
+    int movingCount(int m, int n, int k) {
+        if (m == 0 || n == 0) {
+            return 0;
+        }
+        vector<vector<int>> arr(m, vector<int>(n, 0));
+        int cnt = moving(m, n, arr, 0, 0, k);
+        return cnt;
+    }
+};

lcof/面试题32 - I. 从上到下打印二叉树/Solution.cpp

@@ -0,0 +1,37 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ * };
+ */
+
+class Solution {
+public:
+    vector<int> levelOrder(TreeNode* root) {
+        vector<int> ret;
+        if (!root) {
+            return ret;
+        }
+
+        queue<TreeNode *> q;
+        q.push(root);
+
+        while (!q.empty()) {
+            auto head = q.front();
+            q.pop();
+            ret.push_back(head->val);
+            if (head->left) {
+                q.push(head->left);
+            }
+
+            if (head->right) {
+                q.push(head->right);
+            }
+        }
+
+        return ret;
+    }
+};