Add files via upload (doocs#332)

Author: Stackingrule

solution/0100-0199/0129.Sum Root to Leaf Numbers/Solution.cpp

@@ -0,0 +1,34 @@
+/**
+ * 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:
+    int sumNumbers(TreeNode* root) {
+        if (!root) return 0;
+        int res = 0;
+        stack<TreeNode*> st{{root}};
+        while (!st.empty()) {
+            TreeNode* t = st.top();
+            st.pop();
+            if (!t->left && !t->right) {
+                res += t->val;
+            }
+            if (t->right) {
+                t->right->val += t->val * 10;
+                st.push(t->right);
+            }
+            if (t->left) {
+                t->left->val += t->val * 10;
+                st.push(t->left);
+            }
+        }
+        return res;
+    }
+
+};