第783题

Author: 石荣辉

Week_02/id_65/LeetCode_783_65.java

@@ -0,0 +1,96 @@
+package com.imooc.activiti.helloworld;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+
+/**
+ * @author shironghui on 2019/4/18.
+ */
+class Solution13 {
+
+    List<Integer> list=new ArrayList<>();
+    public int minDiffInBST(TreeNode root) {
+        int min=Integer.MAX_VALUE;
+        dfs(root);
+        for (int i=1;i<list.size();i++){
+            min=Math.min(min,list.get(i)-list.get(i-1));
+        }
+        return min;
+    }
+
+    //中序遍历二叉搜索树，list列表有序
+    private void dfs(TreeNode root) {
+        if(root==null) {
+            return;
+        }
+        dfs(root.left);
+        list.add(root.val);
+        dfs(root.right);
+    }
+
+}
+
+public class TestBinaryTree4 {
+    public static TreeNode stringToTreeNode(String input) {
+        input = input.trim();
+        input = input.substring(1, input.length() - 1);
+        if (input.length() == 0) {
+            return null;
+        }
+
+        String[] parts = input.split(",");
+        String item = parts[0];
+        TreeNode root = new TreeNode(Integer.parseInt(item));
+        Queue<TreeNode> nodeQueue = new LinkedList<>();
+        nodeQueue.add(root);
+
+        int index = 1;
+        while(!nodeQueue.isEmpty()) {
+            TreeNode node = nodeQueue.remove();
+
+            if (index == parts.length) {
+                break;
+            }
+
+            item = parts[index++];
+            item = item.trim();
+            if (!item.equals("null")) {
+                int leftNumber = Integer.parseInt(item);
+                node.left = new TreeNode(leftNumber);
+                nodeQueue.add(node.left);
+            }
+
+            if (index == parts.length) {
+                break;
+            }
+
+            item = parts[index++];
+            item = item.trim();
+            if (!item.equals("null")) {
+                int rightNumber = Integer.parseInt(item);
+                node.right = new TreeNode(rightNumber);
+                nodeQueue.add(node.right);
+            }
+        }
+        return root;
+    }
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
+        String line;
+        while ((line = in.readLine()) != null) {
+            TreeNode root = stringToTreeNode(line);
+
+            int ret = new Solution13().minDiffInBST(root);
+
+            String out = String.valueOf(ret);
+
+            System.out.print(out);
+        }
+    }
+}