diff --git "a/exercise/LC0448_\350\214\203\344\277\256\350\252\211.cpp" "b/exercise/LC0448_\350\214\203\344\277\256\350\252\211.cpp"
new file mode 100644
index 0000000000000000000000000000000000000000..f63262320dc49903b47d5e5a5f340b2270d4adb9
--- /dev/null
+++ "b/exercise/LC0448_\350\214\203\344\277\256\350\252\211.cpp"
@@ -0,0 +1,23 @@
+class Solution {
+public:
+    vector<int> findDisappearedNumbers(vector<int>& nums) {
+        int n = nums.size();
+        vector<int> res;  
+        for(int i=0;i<n;i++)
+        {
+            int x =((nums[i]-1)%n);
+            if(nums[x]<=n)
+            {
+                nums[x]+=n;
+            }
+        }
+        for(int i=0;i<n;i++)
+        {
+            if(nums[i]<=n)
+            {
+                res.push_back(i+1);
+            }
+        }
+        return res;
+    }
+};
diff --git "a/topic02/submit/LC1539_\350\214\203\344\277\256\350\252\211.cpp" "b/topic02/submit/LC1539_\350\214\203\344\277\256\350\252\211.cpp"
new file mode 100644
index 0000000000000000000000000000000000000000..9e43dd4a0c3848964eee1dcbad4323b869dfb586
--- /dev/null
+++ "b/topic02/submit/LC1539_\350\214\203\344\277\256\350\252\211.cpp"
@@ -0,0 +1,20 @@
+class Solution {
+public:
+    int findKthPositive(vector<int>& arr, int k) 
+    {
+        int n = arr.size();
+        if(k<arr[0])
+        {
+            return k;
+        }
+        int l = 0, r = arr.size();
+        while(l != r)
+        {
+            int mid =l +((r-l) >> 1);
+            int x = mid < arr.size() ? arr[mid] : INT_MAX;
+            if(x - mid - 1>=k)r = mid;
+            else l = mid + 1;
+        }
+        return k-(arr[l-1]-(l-1)-1)+arr[l-1];
+    }
+};