diff --git a/Week 01/id_436/Leetcode_26_436.java b/Week 01/id_436/Leetcode_26_436.java
new file mode 100644
index 000000000..a14498af7
--- /dev/null
+++ b/Week 01/id_436/Leetcode_26_436.java	
@@ -0,0 +1,24 @@
+
+/**
+ * 在这里给出对类 Leetcode_26_436 的描述。
+ * 
+ * @作者（你的名字）
+ * @版本（一个版本号或者一个日期）
+ */
+public class Leetcode_26_436
+{
+        public int removeDuplicates(int[] nums) {
+        if(nums.length == 0)
+            return 0;
+        int result = 1;
+        int j = 0;// previous pointer;
+        for(int i = 0; i < nums.length; i++){
+            if(nums[j] != nums[i]){
+                result++;
+                j++;
+                nums[j] = nums[i];
+            }
+        }
+        return result;
+    }
+}
diff --git a/Week 01/id_436/Leetcode_42_436.java b/Week 01/id_436/Leetcode_42_436.java
new file mode 100644
index 000000000..76309d0d1
--- /dev/null
+++ b/Week 01/id_436/Leetcode_42_436.java	
@@ -0,0 +1,28 @@
+/**
+ * 在这里给出对类 Leetcode_42_436 的描述。
+ * 
+ * @作者（你的名字）
+ * @版本（一个版本号或者一个日期）
+ */
+import java.util.*; 
+public class Leetcode_42_436
+{
+    public int trap(int[] height){
+        int n = height.length;
+        Deque<Integer> stack = new ArrayDeque<>();
+        int result = 0;
+        int index = 0;
+        while(index < n){
+            while(!stack.isEmpty() && height[index] > height[stack.peek()]){
+                int top = stack.pop();
+                if(stack.isEmpty()) break;
+                int h = Math.min(height[stack.peek()], height[index]) - height[top];
+                int dist = index - stack.peek() - 1;
+                result += dist * h;
+            }
+            stack.push(index);
+            index++;
+    }
+    return result;
+  }
+}