finish "105. Construct Binary Tree from Preorder and Inorder Traversal". Fix #105

Author: diguage

Diff for: README.adoc

@@ -528,12 +528,12 @@
 //|{leetcode_base_url}/maximum-depth-of-binary-tree/[Maximum Depth of Binary Tree]
 //|{source_base_url}/MaximumDepthOfBinaryTree.java[Java]
 //|Easy
-//
-//|105
-//|{leetcode_base_url}/construct-binary-tree-from-preorder-and-inorder-traversal/[Construct Binary Tree from Preorder and Inorder Traversal]
-//|{source_base_url}/ConstructBinaryTreeFromPreorderAndInorderTraversal.java[Java]
-//|Medium
-//
+
+|105
+|{leetcode_base_url}/construct-binary-tree-from-preorder-and-inorder-traversal/[Construct Binary Tree from Preorder and Inorder Traversal]
+|{source_base_url}/ConstructBinaryTreeFromPreorderAndInorderTraversal.java[Java]
+|Medium
+
 //|106
 //|{leetcode_base_url}/construct-binary-tree-from-inorder-and-postorder-traversal/[Construct Binary Tree from Inorder and Postorder Traversal]
 //|{source_base_url}/ConstructBinaryTreeFromInorderAndPostorderTraversal.java[Java]

Diff for: src/main/java/com/diguage/algorithm/leetcode/ConstructBinaryTreeFromPreorderAndInorderTraversal.java

@@ -0,0 +1,74 @@
+package com.diguage.algorithm.leetcode;
+
+import com.diguage.algorithm.util.JsonUtils;
+import com.diguage.algorithm.util.TreeNode;
+
+/**
+ * = 105. Construct Binary Tree from Preorder and Inorder Traversal
+ *
+ * https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/[Construct Binary Tree from Preorder and Inorder Traversal - LeetCode]
+ *
+ * Given preorder and inorder traversal of a tree, construct the binary tree.
+ *
+ * *Note:*
+ *
+ * You may assume that duplicates do not exist in the tree.
+ *
+ * For example, given
+ *
+ * ----
+ * preorder = [3,9,20,15,7]
+ * inorder = [9,3,15,20,7]
+ * ----
+ *
+ * Return the following binary tree:
+ *
+ * ----
+ *     3
+ *    / \
+ *   9  20
+ *     /  \
+ *    15   7
+ * ----
+ *
+ * @author D瓜哥, https://www.diguage.com/
+ * @since 2020-01-04 20:25
+ */
+public class ConstructBinaryTreeFromPreorderAndInorderTraversal {
+    /**
+     * Runtime: 10 ms, faster than 34.14% of Java online submissions for Construct Binary Tree from Preorder and Inorder Traversal.
+     *
+     * Memory Usage: 36.1 MB, less than 100.00% of Java online submissions for Construct Binary Tree from Preorder and Inorder Traversal.
+     *
+     * Copy from: https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/discuss/34538/My-Accepted-Java-Solution[My Accepted Java Solution - LeetCode Discuss]
+     */
+    public TreeNode buildTree(int[] preorder, int[] inorder) {
+        return build(preorder, inorder, 0, 0, inorder.length);
+    }
+
+    private TreeNode build(int[] preorder, int[] inorder, int preStart, int inStart, int inEnd) {
+        if (preStart > preorder.length - 1 || inStart > inEnd) {
+            return null;
+        }
+        int value = preorder[preStart];
+        int index = inStart;
+        for (int i = inStart; i <= inEnd; i++) {
+            if (inorder[i] == value) {
+                index = i;
+                break;
+            }
+        }
+        TreeNode root = new TreeNode(value);
+        root.left = build(preorder, inorder, preStart + 1, inStart, index - 1);
+        root.right = build(preorder, inorder, preStart + (index - inStart) + 1, index + 1, inEnd);
+        return root;
+    }
+
+    public static void main(String[] args) {
+        ConstructBinaryTreeFromPreorderAndInorderTraversal solution = new ConstructBinaryTreeFromPreorderAndInorderTraversal();
+        int[] preorder = {3, 9, 20, 15, 7};
+        int[] inorder = {9, 3, 15, 20, 7};
+        TreeNode tree = solution.buildTree(preorder, inorder);
+        System.out.println(JsonUtils.toJson(tree));
+    }
+}

Diff for: src/main/java/com/diguage/algorithm/util/JsonUtils.java

@@ -0,0 +1,22 @@
+package com.diguage.algorithm.util;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * @author D瓜哥, https://www.diguage.com/
+ * @since 2020-01-04 20:28
+ */
+public class JsonUtils {
+    private static final ObjectMapper MAPPER = new ObjectMapper();
+
+    public static String toJson(Object object) {
+        String result = null;
+        try {
+            result = MAPPER.writeValueAsString(object);
+        } catch (JsonProcessingException e) {
+            e.printStackTrace();
+        }
+        return result;
+    }
+}