diff --git "a/topic02/submit/LC0222_\345\274\240\344\270\226\344\273\273.cpp" "b/topic02/submit/LC0222_\345\274\240\344\270\226\344\273\273.cpp"
new file mode 100644
index 0000000000000000000000000000000000000000..199090a81445884add284ecb6f7189adb002ee53
--- /dev/null
+++ "b/topic02/submit/LC0222_\345\274\240\344\270\226\344\273\273.cpp"
@@ -0,0 +1,30 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+#include <iostream>
+using namespace std;
+class Solution {
+public:
+void iscomplete(TreeNode* node,int &count){
+    if(!node){return;}
+    if(node->left||(!node->left&&!node->right)){
+        count++;
+    }
+   if(node->left){iscomplete(node->left,count);}
+    if(node->right){iscomplete(node->right,count);}
+}
+    int countNodes(TreeNode* root) {
+        if(!root){return 0;}
+        int count=0;
+        iscomplete(root,count);
+        return count;
+    }
+};
\ No newline at end of file
diff --git "a/topic02/submit/LC1552_\345\274\240\344\270\226\344\273\2731.cpp" "b/topic02/submit/LC1552_\345\274\240\344\270\226\344\273\2731.cpp"
new file mode 100644
index 0000000000000000000000000000000000000000..3ae286f05dbb7f39353fef9d3cf8cd74bba1dcc3
--- /dev/null
+++ "b/topic02/submit/LC1552_\345\274\240\344\270\226\344\273\2731.cpp"
@@ -0,0 +1,55 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include <climits> // 包含INT_MAX的定义
+using namespace std;
+
+class Solution {
+public:
+    // 验证函数：判断能否以至少x的间距放置m个球
+    bool check(int x, vector<int>& a, int m) {
+        int cnt = 0; // 记录已形成的有效间隔数（m个球需要m-1个间隔）
+        int target = a[0] + x; // 第一个球放在a[0]，下一个球的最小位置
+        for (int i = 0; i < a.size() - 1; i++) {
+            // 找到第一个>=target的位置，放置下一个球
+            if (a[i] < target && a[i + 1] >= target) {
+                cnt++;
+                target = a[i + 1] + x; // 更新下一个球的最小位置
+            }
+        }
+        return cnt >= m - 1; // 间隔数足够则返回true
+    }
+    
+    int maxDistance(vector<int>& position, int m) {
+        vector<int>& a = position; // 统一变量名，避免混淆
+        sort(a.begin(), a.end()); // 排序位置数组（必须先排序）
+        int len = a.size();
+        int maxd = a[len - 1] - a[0]; // 最大可能间距（首尾差）
+        int mind = INT_MAX; // 最小可能间距（相邻元素的最小差）
+        
+        // 计算相邻元素的最小间距
+        for (int i = 0; i < len - 1; i++) {
+            mind = min(mind, a[i + 1] - a[i]);
+        }
+        
+        // 特判：m=2时，最大间距就是首尾差
+        if (m == 2) {
+            return maxd;
+        } else {
+            // 二分查找：左边界为最小间距，右边界为理论最大可能的最小间距
+            int l = mind;
+            int r = maxd / (m - 1);
+            while (l <= r) {
+                int mid = (l + r) / 2; // 当前猜测的最小间距
+                if (check(mid, a, m)) {
+                    // 能放下，尝试更大的间距
+                    l = mid + 1;
+                } else {
+                    // 放不下，尝试更小的间距
+                    r = mid - 1;
+                }
+            }
+            return l - 1; // 退出时l-1是最大有效间距
+        }
+    }
+};
\ No newline at end of file
diff --git "a/topic03/submit/LC0053_\345\274\240\344\270\226\344\273\273.cpp" "b/topic03/submit/LC0053_\345\274\240\344\270\226\344\273\273.cpp"
new file mode 100644
index 0000000000000000000000000000000000000000..1d45686c1f50f393b5b08fbf8acf91442b10306d
--- /dev/null
+++ "b/topic03/submit/LC0053_\345\274\240\344\270\226\344\273\273.cpp"
@@ -0,0 +1,14 @@
+class Solution {
+public:
+    int maxSubArray(vector<int>& nums) {
+        int ans=INT_MIN;
+        int min_presum=0;
+        int presum=0;
+        for(int x:nums){
+            presum+=x;
+            ans=max(ans,presum-min_presum);
+            min_presum=min(min_presum,presum);
+        }
+        return ans;
+    }
+};
\ No newline at end of file
diff --git "a/topic03/submit/LC1685_\345\274\240\344\270\226\344\273\273.cpp" "b/topic03/submit/LC1685_\345\274\240\344\270\226\344\273\273.cpp"
new file mode 100644
index 0000000000000000000000000000000000000000..c72cbd33e00a8e239261122400faff8ac7fa984a
--- /dev/null
+++ "b/topic03/submit/LC1685_\345\274\240\344\270\226\344\273\273.cpp"
@@ -0,0 +1,16 @@
+class Solution {
+public:
+    vector<int> getSumAbsoluteDifferences(vector<int>& nums) {
+        int n=nums.size();
+        int sum=0;
+        for(auto m:nums){
+            sum+=m;
+        }
+        int presum=0;
+        for(int i=0;i<n;i++){
+            presum+=nums[i];
+            nums[i]=(nums[i]*(i+1)-presum)+(sum-presum-(n-i-1)*nums[i]);
+        }
+        return nums;
+    }
+};
\ No newline at end of file
diff --git "a/topic03/submit/LC2143_\345\274\240\344\270\226\344\273\273.cpp" "b/topic03/submit/LC2143_\345\274\240\344\270\226\344\273\273.cpp"
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391