diff --git a/code/src/main/java/com/raorao/java/Test.java b/code/src/main/java/com/raorao/java/Test.java
index d1774164..c5ce698e 100644
--- a/code/src/main/java/com/raorao/java/Test.java
+++ b/code/src/main/java/com/raorao/java/Test.java
@@ -1,6 +1,9 @@
 package com.raorao.java;
 
+import clojure.lang.Obj;
 import com.google.common.collect.HashBasedTable;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
 import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.Hashtable;
@@ -9,7 +12,7 @@ import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.Map.Entry;
 
-public class Test {
+public class Test implements Serializable {
 
   static int a;
   static int c;
diff --git a/code/src/main/java/com/raorao/java/althorithm/Hanuota.java b/code/src/main/java/com/raorao/java/althorithm/Hanuota.java
new file mode 100644
index 00000000..cf9ff36b
--- /dev/null
+++ b/code/src/main/java/com/raorao/java/althorithm/Hanuota.java
@@ -0,0 +1,32 @@
+package com.raorao.java.althorithm;
+
+import java.util.Stack;
+
+/**
+ * 汉诺塔问题.
+ *
+ * 描述：三个柱子，其中一个柱子有N个盘子，要求移动到另外一个盘子上。
+ *
+ * @author Xiong Raorao
+ * @since 2018-08-17-16:41
+ */
+public class Hanuota {
+
+  static int count = 0;
+
+  public static void main(String[] args) {
+    move(3, "A", "B", "C");
+    System.out.println("times: " + count);
+  }
+
+  public static void move(int n, String A, String B, String C) {
+    if (n == 1) {
+      System.out.println(A + " ==> " + C);
+      count++;
+      return;
+    }
+    move(n - 1, A, C, B);
+    move(1, A, B, C);
+    move(n - 1, B, A, C);
+  }
+}
diff --git a/code/src/main/java/com/raorao/leetcode/q167/TwoSum.java b/code/src/main/java/com/raorao/leetcode/q167/TwoSum.java
new file mode 100644
index 00000000..f36bea12
--- /dev/null
+++ b/code/src/main/java/com/raorao/leetcode/q167/TwoSum.java
@@ -0,0 +1,39 @@
+package com.raorao.leetcode.q167;
+
+/**
+ * 有序数组的和.
+ *
+ * @author Xiong Raorao
+ * @since 2018-08-17-17:38
+ */
+public class TwoSum {
+
+  public static void main(String[] args) {
+    int[] numbers = {2, 7, 11, 15};
+    int target = 9;
+    int[] res = twoSum(numbers, target);
+    System.out.println(res[0] + " " + res[1]);
+  }
+
+  public static int[] twoSum(int[] numbers, int target) {
+    if (numbers == null || numbers.length == 0) {
+      return new int[0];
+    }
+    int[] res = new int[2];
+    int size = numbers.length;
+    int low = 0;
+    int high = size - 1;
+    while (low < high) {
+      if (numbers[low] + numbers[high] == target) {
+        res[0] = low + 1;
+        res[1] = high + 1;
+        break;
+      } else if (numbers[low] + numbers[high] < target) {
+        low++;
+      } else {
+        high--;
+      }
+    }
+    return res;
+  }
+}
diff --git a/code/src/main/java/com/raorao/leetcode/q406/Solution.java b/code/src/main/java/com/raorao/leetcode/q406/Solution.java
new file mode 100644
index 00000000..489eea0d
--- /dev/null
+++ b/code/src/main/java/com/raorao/leetcode/q406/Solution.java
@@ -0,0 +1,18 @@
+package com.raorao.leetcode.q406;
+
+/**
+ * 根据身高和序号重组队列.
+ *
+ * @author Xiong Raorao
+ * @since 2018-08-17-15:22
+ */
+public class Solution {
+
+  public static void main(String[] args) {
+
+  }
+
+  public int[][] reconstructQueue(int[][] people) {
+    return null;
+  }
+}
diff --git a/code/src/main/java/com/raorao/leetcode/q435/Solution.java b/code/src/main/java/com/raorao/leetcode/q435/Solution.java
index 28a01579..53a5a96f 100644
--- a/code/src/main/java/com/raorao/leetcode/q435/Solution.java
+++ b/code/src/main/java/com/raorao/leetcode/q435/Solution.java
@@ -4,7 +4,7 @@ import java.util.Arrays;
 import java.util.Comparator;
 
 /**
- * 题目描述：计算让一组区间不重叠所需要移除的区间个数.
+ * 题目描述：计算让一组区间不重叠所需要移除的最少区间个数.
  *
  * 贪心策略：计算最多能组成的不重叠区间个数，然后用区间总个数减去不重叠区间的个数。
  *
diff --git a/code/src/main/java/com/raorao/leetcode/q452/Solution.java b/code/src/main/java/com/raorao/leetcode/q452/Solution.java
new file mode 100644
index 00000000..99fc15e1
--- /dev/null
+++ b/code/src/main/java/com/raorao/leetcode/q452/Solution.java
@@ -0,0 +1,48 @@
+package com.raorao.leetcode.q452;
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+/**
+ * 用最少数量的箭引爆气球.
+ *
+ * 思路：其实和计算不重叠区间的是一样的，
+ *
+ * @author Xiong Raorao
+ * @since 2018-08-17-14:53
+ */
+public class Solution {
+
+  public int findMinArrowShots(int[][] points) {
+    if (points == null || points.length == 0) {
+      return 0;
+    }
+    Point[] p = new Point[points.length];
+    for (int i = 0; i < points.length; i++) {
+      p[i] = new Point(points[i][0], points[i][1]);
+    }
+    Arrays.sort(p, Comparator.comparingInt(e -> e.end));
+    int count = 1;
+    int lastEnd = p[0].end;
+    for (int i = 1; i < p.length; i++) {
+      if (p[i].start <= lastEnd) {
+        continue;
+      }
+      lastEnd = p[i].end;
+      count++;
+    }
+    return p.length - count;
+  }
+
+  static class Point {
+
+    int start;
+    int end;
+
+
+    public Point(int start, int end) {
+      this.start = start;
+      this.end = end;
+    }
+  }
+}
diff --git a/interview/README.md b/interview/README.md
index 1b4e383b..fa122bf6 100644
--- a/interview/README.md
+++ b/interview/README.md
@@ -2,9 +2,6 @@
 
 目标职位： java 工程师、大数据开发方向 
 
-[简历](熊饶饶-校招简历-0717.pdf)  
-[头像](我的头像.jpg)
-
 ## 1. 招聘信息
 
 招聘信息的来源主要是学校的群和牛客网。
diff --git a/interview/我的头像.jpg b/interview/我的头像.jpg
deleted file mode 100644
index 88fb5b83..00000000
Binary files a/interview/我的头像.jpg and /dev/null differ
diff --git a/interview/熊饶饶-校招简历-0717.pdf b/interview/熊饶饶-校招简历-0717.pdf
deleted file mode 100644
index c5508993..00000000
Binary files a/interview/熊饶饶-校招简历-0717.pdf and /dev/null differ