diff --git a/Week_02/week02.cpp b/Week_02/week02.cpp
new file mode 100644
index 00000000..cbdedc14
--- /dev/null
+++ b/Week_02/week02.cpp
@@ -0,0 +1,62 @@
+//有效的字母异位词
+class Solution {
+public:
+    bool isAnagram(string s, string t) {
+        if(t.empty()) {
+            if(s.empty()) {
+                return true;
+            }
+            else {
+                return false;
+            }
+        }
+        else {
+            if(t.size() != s.size()) {
+                return false;
+            }
+        }
+        
+        map<char, int> map_s;
+        map<char, int> map_t;
+        for(auto var : s) {
+            map_s[var]++;
+        }
+        for(auto var : t) {
+            map_t[var]++;
+        }
+        for(auto var : map_s) {
+            if(map_t.find(var.first) == map_t.end() ||
+            map_t[var.first] != var.second) {
+                return false;
+            }
+        }
+        return true;
+    }
+};
+
+//前 K 个高频元素
+class Solution {
+public:
+    vector<int> topKFrequent(vector<int>& nums, int k) {
+        map<int, int> cnt_list;
+        for(int num : nums) {
+            cnt_list[num]++;
+        }
+
+        priority_queue<pair<int, int>> queue;
+        for(auto& var : cnt_list) {
+            pair<int, int> info;
+            info.first = var.second;
+            info.second = var.first;
+            queue.push(info);
+        }
+
+        vector<int> res;
+        for(int i=0; i<k; i++) {
+            pair<int, int> info = queue.top();
+            res.push_back(info.second);
+            queue.pop();
+        }
+        return res;
+    }
+};
\ No newline at end of file
diff --git a/Week_04/lemonadeChange.py b/Week_04/lemonadeChange.py
new file mode 100644
index 00000000..cab78117
--- /dev/null
+++ b/Week_04/lemonadeChange.py
@@ -0,0 +1,26 @@
+class Solution:
+    def lemonadeChange(self, bills: List[int]) -> bool:
+        if not bills:
+            return False
+
+        changes = []
+        for num in bills:
+            if num == 5:
+                changes.append(num)
+            else:
+                rest = num - 5
+                changes.sort(reverse = True)
+                index = []
+                for i, change in enumerate(changes):
+                    if rest >= change:
+                        rest -= change
+                        index.append(i)
+                        if rest == 0:
+                            break
+                if rest == 0:
+                    for j in reversed(index):
+                        changes.pop(j)
+                    changes.append(num)
+                else:
+                    return False
+        return True
\ No newline at end of file
diff --git a/Week_04/searchMatrix.cpp b/Week_04/searchMatrix.cpp
new file mode 100644
index 00000000..f8941d65
--- /dev/null
+++ b/Week_04/searchMatrix.cpp
@@ -0,0 +1,28 @@
+class Solution {
+public:
+    bool searchMatrix(vector<vector<int>>& matrix, int target) {
+        if(matrix.empty()) {
+            return false;
+        }
+
+        int m = matrix.size();
+        int n = matrix[0].size();
+        int left = 0;
+        int right = m*n - 1;
+        while(left <= right) {
+            int mid = left + (right-left)/2;
+            int row = mid/n;
+            int col = mid%n;
+            if(matrix[row][col] == target) {
+                return true;
+            }
+            else if(matrix[row][col] < target) {
+                left = mid + 1;
+            }
+            else {
+                right = mid - 1;
+            }
+        }
+        return false;
+    }
+};
\ No newline at end of file
diff --git a/Week_06/longestValidParentheses.cpp b/Week_06/longestValidParentheses.cpp
new file mode 100644
index 00000000..ce7980b6
--- /dev/null
+++ b/Week_06/longestValidParentheses.cpp
@@ -0,0 +1,21 @@
+class Solution {
+public:
+    int longestValidParentheses(string s) {
+        int maxans = 0;
+        stack<int> stk;
+        stk.push(-1);
+        for (int i = 0; i < s.length(); i++) {
+            if (s[i] == '(') {
+                stk.push(i);
+            } else {
+                stk.pop();
+                if (stk.empty()) {
+                    stk.push(i);
+                } else {
+                    maxans = max(maxans, i - stk.top());
+                }
+            }
+        }
+        return maxans;
+    }
+};
\ No newline at end of file
diff --git a/Week_06/minPathSum.cpp b/Week_06/minPathSum.cpp
new file mode 100644
index 00000000..3ae60cce
--- /dev/null
+++ b/Week_06/minPathSum.cpp
@@ -0,0 +1,36 @@
+class Solution {
+public:
+    int minPathSum(vector<vector<int>>& grid) {
+        int m = grid.size();
+        int n = grid[0].size();
+        vector<vector<int>> dp;
+        dp.resize(m);
+        for(int i=0; i<m; i++) {
+            dp[i].resize(n);
+        }
+        for(int i=0; i<m; i++) {
+            for(int j=0; j<n; j++) {
+                dp[i][j] = 0;
+            }
+        }
+        for(int i=0; i<m; i++) {
+            for(int j=0; j<n; j++) {
+                if(i == 0 && j == 0) {
+                    dp[i][j] = grid[i][j];
+                }
+                else {
+                    if(i == 0) {
+                        dp[i][j] = dp[i][j-1] + grid[i][j];
+                    }
+                    else if(j == 0) {
+                        dp[i][j] = dp[i-1][j] + grid[i][j];
+                    }
+                    else {
+                        dp[i][j] = min(dp[i-1][j], dp[i][j-1]) + grid[i][j]; 
+                    }
+                }
+            }
+        }
+        return dp[m-1][n-1];
+    }
+};
\ No newline at end of file
diff --git a/Week_07/generateParenthesis.cpp b/Week_07/generateParenthesis.cpp
new file mode 100644
index 00000000..d187a9ef
--- /dev/null
+++ b/Week_07/generateParenthesis.cpp
@@ -0,0 +1,25 @@
+class Solution {
+public:
+    vector<string> result;
+    void dfs(string cur_str, int left, int right, int n) {
+        if(left == n && right == n) {
+            result.push_back(cur_str);
+            return;
+        }
+        if(left < right) {
+            return;
+        }
+
+        if(left < n) {
+            dfs(cur_str+"(", left+1, right, n);
+        }
+        if(right < n) {
+            dfs(cur_str+")", left, right+1, n);
+        }
+    }
+
+    vector<string> generateParenthesis(int n) {
+        dfs("", 0, 0, n);
+        return result;
+    }
+};
\ No newline at end of file
diff --git a/Week_07/ladderLength.cpp b/Week_07/ladderLength.cpp
new file mode 100644
index 00000000..12a4d972
--- /dev/null
+++ b/Week_07/ladderLength.cpp
@@ -0,0 +1,43 @@
+class Solution {
+public:
+    int ladderLength(string beginWord, string endWord, vector<string>& wordList) {
+        set<string> wordSet;
+        for(string& word : wordList) {
+            wordSet.insert(word);
+        }
+        if(wordSet.find(endWord) == wordSet.end()) {
+            return 0;
+        }
+
+        deque<string> queue;
+        queue.push_back(beginWord);
+        int len = 1;
+        while(!queue.empty()) {
+            int size = queue.size();
+            for(int i=0; i<size; i++) {
+                string word = queue.front();
+                queue.pop_front();
+                int length = word.size();
+                for(int i=0; i<length; i++) {
+                    string temp = word;
+                    for(char ch='a'; ch<='z'; ch++) {
+                        if(ch == temp[i]) {
+                            continue;
+                        }
+                        temp[i] = ch;
+                        if(temp == endWord) {
+                            return len+1;
+                        }
+                        auto iter = wordSet.find(temp);
+                        if(iter != wordSet.end()) {
+                            queue.push_back(temp);
+                            wordSet.erase(iter);
+                        }
+                    }
+                }
+            }
+            ++len;
+        }
+        return 0;
+    }
+};
\ No newline at end of file
diff --git a/Week_08/Trie.cpp b/Week_08/Trie.cpp
new file mode 100644
index 00000000..d8c1cc8a
--- /dev/null
+++ b/Week_08/Trie.cpp
@@ -0,0 +1,96 @@
+class TrieNode {
+public:
+    TrieNode() {
+        links.reserve(num);
+        for(int i=0; i<num; i++) {
+            links[i] = NULL;
+        }
+    }
+
+    bool containsKey(char ch) {
+        return links[ch-'a'] != NULL;
+    }
+
+    TrieNode* get(char ch) {
+        return links[ch-'a'];
+    }
+
+    void put(char ch, TrieNode* node) {
+        links[ch-'a'] = node;
+    }
+
+    void setEnd() {
+        is_end = true;
+    }
+
+    bool isEnd() {
+        return is_end;
+    }
+
+private:
+    vector<TrieNode*> links;
+    int num = 26;
+    bool is_end = false;
+};
+
+class Trie {
+public:
+    /** Initialize your data structure here. */
+    Trie() {
+        root = new TrieNode();
+    }
+    
+    /** Inserts a word into the trie. */
+    void insert(string word) {
+        TrieNode *node = root;
+        int length = word.size();
+        for(int i=0; i<length; i++) {
+            if(!node->containsKey(word[i])) {
+                TrieNode *_node = new TrieNode();
+                node->put(word[i], _node);
+            }
+            node = node->get(word[i]);
+        }
+        node->setEnd();
+    }
+    
+    /** Returns if the word is in the trie. */
+    bool search(string word) {
+        TrieNode *node = root;
+        int length = word.size();
+        for(int i=0; i<length; i++) {
+            if(node->containsKey(word[i])) {
+                node = node->get(word[i]);
+            }
+            else {
+                return false;
+            }
+        }
+        return (node && node->isEnd());
+    }
+    
+    /** Returns if there is any word in the trie that starts with the given prefix. */
+    bool startsWith(string prefix) {
+        TrieNode *node = root;
+        int length = prefix.size();
+        for(int i=0; i<length; i++) {
+            if(node->containsKey(prefix[i])) {
+                node = node->get(prefix[i]);
+            }
+            else {
+                return false;
+            }
+        }
+        return true;
+    }
+private:
+    TrieNode *root;
+};
+
+/**
+ * Your Trie object will be instantiated and called as such:
+ * Trie* obj = new Trie();
+ * obj->insert(word);
+ * bool param_2 = obj->search(word);
+ * bool param_3 = obj->startsWith(prefix);
+ */
\ No newline at end of file
diff --git a/Week_08/findCircleNum.cpp b/Week_08/findCircleNum.cpp
new file mode 100644
index 00000000..e6ecb36e
--- /dev/null
+++ b/Week_08/findCircleNum.cpp
@@ -0,0 +1,35 @@
+class Solution {
+public:
+    int find(vector<int>& parent, int index) {
+        if (parent[index] != index) {
+            parent[index] = find(parent, parent[index]);
+        }
+        return parent[index];
+    }
+
+    void joint(vector<int>& parent, int index1, int index2) {
+        parent[find(parent, index1)] = find(parent, index2);
+    }
+
+    int findCircleNum(vector<vector<int>>& isConnected) {
+        int provinces = isConnected.size();
+        vector<int> parent(provinces);
+        for (int i = 0; i < provinces; i++) {
+            parent[i] = i;
+        }
+        for (int i = 0; i < provinces; i++) {
+            for (int j = i + 1; j < provinces; j++) {
+                if (isConnected[i][j] == 1) {
+                    joint(parent, i, j);
+                }
+            }
+        }
+        int circles = 0;
+        for (int i = 0; i < provinces; i++) {
+            if (parent[i] == i) {
+                circles++;
+            }
+        }
+        return circles;
+    }
+};
\ No newline at end of file
diff --git "a/Week_10 \346\257\225\344\270\232\346\200\273\347\273\223/\346\257\225\344\270\232\346\200\273\347\273\223.md" "b/Week_10 \346\257\225\344\270\232\346\200\273\347\273\223/\346\257\225\344\270\232\346\200\273\347\273\223.md"
new file mode 100644
index 00000000..c3610b25
--- /dev/null
+++ "b/Week_10 \346\257\225\344\270\232\346\200\273\347\273\223/\346\257\225\344\270\232\346\200\273\347\273\223.md"	
@@ -0,0 +1 @@
+时间过得真快，一转眼这一期的算法训练营就结束了，对于一个不够勤奋的我来说，有遗憾也有收获，遗憾的是刷的题目不够多，有些地方理解的还不够深刻，比如动态规划，需要后续跟进。收获的是算法的系统学习，虽然之前也零零碎碎的接触到一些算法方面的内容，但是不够系统，没有站在一个更高的角度来看待算法，尤其是老师强调计算机处理复杂问题的重复解时的几个特征，还有就是一定要动手，能看懂和能写出来完全是两码事，而且有些题目时间长了自己可能已经忘了当时是怎么做的，这个是正常现象，所以正如老师强调的“五毒神掌”那样要过遍数，归根结底还是要刻意练习，希望在未来的日子里把遗憾补上，做更好的自己！
\ No newline at end of file