finish "129. Sum Root to Leaf Numbers". Fix #129

Author: diguage

README.adoc

@@ -777,12 +777,12 @@
 //|{source_base_url}/_0128_LongestConsecutiveSequence.java[Java]
 //|{doc_base_url}/0128-longest-consecutive-sequence.adoc[Note]
 //|Hard
-//
-//|129
-//|{leetcode_base_url}/sum-root-to-leaf-numbers/[Sum Root to Leaf Numbers]
-//|{source_base_url}/_0129_SumRootToLeafNumbers.java[Java]
-//|{doc_base_url}/0129-sum-root-to-leaf-numbers.adoc[Note]
-//|Medium
+
+|129
+|{leetcode_base_url}/sum-root-to-leaf-numbers/[Sum Root to Leaf Numbers]
+|{source_base_url}/_0129_SumRootToLeafNumbers.java[Java]
+|{doc_base_url}/0129-sum-root-to-leaf-numbers.adoc[Note]
+|Medium
 
 |130
 |{leetcode_base_url}/surrounded-regions/[Surrounded Regions]

docs/0112-path-sum.adoc

@@ -28,3 +28,6 @@ return true, as there exist a root-to-leaf path `5->4->11->2` which sum is 22.
 减去当前节点值的只，然后递归调用，到叶子节点和目标值相等即可。
 
 注意把代码写简化点！
+
+这道题和 xref:0129-sum-root-to-leaf-numbers.adoc[129. Sum Root to Leaf Numbers] 类似。
+

docs/0129-sum-root-to-leaf-numbers.adoc

@@ -43,3 +43,18 @@ The root-to-leaf path `4->0` represents the number 40.
 Therefore, sum = 495 + 491 + 40 = `1026`.
 ----
 
+=== 解题分析
+
+这道题和 xref:0112-path-sum.adoc[112. Path Sum] 类似。
+
+找到所有路径，父级乘以10，再加当前节点，最后到叶子节点时，加入到总和中。
+
+=== 思考题
+
+. 尝试使用中根遍历和后跟遍历的解法。
+. 目前解法是会用了实例变量，能否取去掉？
+
+=== 参考资料
+
+. https://leetcode-cn.com/problems/sum-root-to-leaf-numbers/solution/3zhong-jie-fa-di-gui-xian-xu-fei-di-gui-xian-xu-ce/[3中解法：递归先序、非递归先序、层序 - 求根到叶子节点数字之和 - 力扣（LeetCode）]
+. https://leetcode-cn.com/problems/sum-root-to-leaf-numbers/solution/xiang-xi-tong-su-de-si-lu-fen-xi-duo-jie-fa-by-3-5/[详细通俗的思路分析，多解法 - 求根到叶子节点数字之和 - 力扣（LeetCode）]

src/main/java/com/diguage/algorithm/leetcode/_0129_SumRootToLeafNumbers.java

@@ -0,0 +1,55 @@
+package com.diguage.algorithm.leetcode;
+
+import com.diguage.algorithm.util.TreeNode;
+
+import java.util.Objects;
+
+import static com.diguage.algorithm.util.TreeNodeUtils.buildTree;
+import static java.util.Arrays.asList;
+
+/**
+ * = 129. Sum Root to Leaf Numbers
+ *
+ * https://leetcode.com/problems/sum-root-to-leaf-numbers/[Sum Root to Leaf Numbers - LeetCode]
+ *
+ * @author D瓜哥, https://www.diguage.com/
+ * @since 2020-02-07 23:56
+ */
+public class _0129_SumRootToLeafNumbers {
+
+    /**
+     * Runtime: 0 ms, faster than 100.00% of Java online submissions for Sum Root to Leaf Numbers.
+     * Memory Usage: 37.7 MB, less than 5.13% of Java online submissions for Sum Root to Leaf Numbers.
+     */
+    private int sum = 0;
+    public int sumNumbers(TreeNode root) {
+        dfs(root, 0);
+        return sum;
+    }
+
+    private void dfs(TreeNode root, int parent) {
+        if (Objects.isNull(root)) {
+            return;
+        }
+        int temp = parent * 10 + root.val;
+        if (Objects.isNull(root.left) && Objects.isNull(root.right)) {
+            sum += temp;
+            return;
+        }
+        dfs(root.left, temp);
+        dfs(root.right, temp);
+    }
+
+
+    public static void main(String[] args) {
+        _0129_SumRootToLeafNumbers solution = new _0129_SumRootToLeafNumbers();
+
+        solution.sum = 0;
+        int r1 = solution.sumNumbers(buildTree(asList(1, 2, 3)));
+        System.out.println((r1 == 25) + " : " + r1);
+
+        solution.sum = 0;
+        int r2 = solution.sumNumbers(buildTree(asList(4, 9, 0, 5, 1)));
+        System.out.println((r2 == 1026) + " : " + r2);
+    }
+}