diff --git a/container-with-most-water/se6816.java b/container-with-most-water/se6816.java
new file mode 100644
index 0000000000..a226f29aa4
--- /dev/null
+++ b/container-with-most-water/se6816.java
@@ -0,0 +1,47 @@
+/**
+	브루트포스를 통해 모든 경우의 수를 연산하여 찾는 방식
+	배열 height의 길이 -> N 
+	시간 복잡도 : O(N^2) -> 시간 초과
+	공간 복잡도 : O(1)
+*/
+class FailSolution {
+    public int maxArea(int[] height) {
+        int max=0;
+        int area=0;
+        for(int i=0;i<height.length;i++){
+            for(int j=i+1;j<height.length;j++){
+                area= Math.max(area,Math.min(height[j],height[i])*(j-i));
+                if(area>max){
+                    max=area;
+                }
+            }
+        }
+        return max;
+    }
+}
+
+/**
+	투포인터를 활용하여, 낮은 높이의 포인터를 갱신하면서 최대 넓이를 구하는 방식
+	배열 height의 길이 -> N 
+	시간 복잡도 : O(N)
+	공간 복잡도 : O(1)
+*/
+class Solution {
+    public int maxArea(int[] height) {
+        int left = 0;
+        int right = height.length - 1;
+        int max = 0;
+        while(left < right) {
+            int h = Math.min(height[right], height[left]);
+            int w = right - left;
+            max = Math.max(max, w * h);
+
+            if(h == height[right]) {
+                right--;
+            } else {
+                left++;
+            }
+        }
+        return max;
+    }
+}
diff --git a/design-add-and-search-words-data-structure/se6816.java b/design-add-and-search-words-data-structure/se6816.java
new file mode 100644
index 0000000000..c498fe9982
--- /dev/null
+++ b/design-add-and-search-words-data-structure/se6816.java
@@ -0,0 +1,116 @@
+/**
+	Tries + BFS를 활용한 방식
+	addWord()
+	문자열 word의 길이 -> N
+	시간 복잡도 : O(N) 
+	공간 복잡도 : O(N)
+	search()
+	Tries 내부의 노드 개수 -> M
+	시간 복잡도 : O(M)
+	공간 복잡도 : O(M)
+*/
+class WordDictionary {
+    public Map<Character, WordNode> wordMap;
+
+    public WordDictionary() {
+        wordMap = new HashMap<>();
+    }
+    
+    public void addWord(String word) {
+        WordNode wordNode = null;
+        char ch = word.charAt(0);
+        wordNode = wordMap.get(ch);
+
+        if(wordNode == null) {
+            boolean isFirstWord = word.length() == 1;
+            wordNode = new WordNode(ch, isFirstWord);
+            wordMap.put(ch, wordNode);
+        }
+
+        for(int idx = 1; idx < word.length(); idx++) {
+            char target = word.charAt(idx);
+            boolean isLeaf = word.length() - 1 == idx;
+            wordNode = wordNode.next.computeIfAbsent(target, key -> new WordNode(key, isLeaf));
+        }
+        wordNode.isLeaf = true;
+        
+        
+    }
+    
+    public boolean search(String word) {
+        Queue<Node> que = new ArrayDeque<>();
+        boolean result = false;
+        char ch = word.charAt(0);
+        WordNode wordNode = wordMap.get(ch);
+        int len = word.length();
+
+        if(ch == '.' && wordMap.size() != 0) {
+            for(Map.Entry<Character, WordNode> entry : wordMap.entrySet()) {
+                que.add(new Node(entry.getValue(), 1));
+            }
+        }
+
+        if (wordNode != null) {
+            que.add(new Node(wordNode, 1));
+        }
+
+
+
+        while(!que.isEmpty()) {
+            Node node = que.poll();
+            if(node.idx == len && node.wordNode.isLeaf) {
+                result = true;
+                break;
+            }
+
+            if(node.idx == len) {
+                continue;
+            }
+
+            char target = word.charAt(node.idx);
+
+            if(target == '.' && node.wordNode.next.size() != 0) {
+                for(Map.Entry<Character, WordNode> entry : node.wordNode.next.entrySet()) {
+                    que.add(new Node(entry.getValue(), node.idx + 1));
+                }
+                continue;
+            }
+
+
+            if (!node.wordNode.next.containsKey(target)) {
+                continue;
+            }
+
+            que.add(new Node(node.wordNode.next.get(target), node.idx + 1));
+        }
+
+        return result;
+        
+    }
+}
+
+class Node {
+    WordNode wordNode;
+    int idx;
+    public Node(WordNode wordNode, int idx) {
+        this.wordNode = wordNode;
+        this.idx = idx;
+    }
+}
+
+class WordNode {
+    char ch;
+    Map<Character, WordNode> next;
+    boolean isLeaf;
+
+    public WordNode(char ch) {
+        this(ch, false);
+    }
+    
+    public WordNode(char ch, boolean isLeaf) {
+        next = new HashMap<>();
+        this.ch = ch;
+        this.isLeaf = isLeaf;
+    }
+
+}
diff --git a/longest-increasing-subsequence/se6816.java b/longest-increasing-subsequence/se6816.java
new file mode 100644
index 0000000000..eae7619b2b
--- /dev/null
+++ b/longest-increasing-subsequence/se6816.java
@@ -0,0 +1,59 @@
+/**
+	dp를 활용한 방식
+	nums의 길이 -> N
+	시간 복잡도 : O(N)
+	공간 복잡도 : O(N)
+*/
+class Solution {
+   public int lengthOfLIS(int[] nums) {
+        int[] dp =new int[nums.length];
+        for(int i = 0; i < dp.length; i++) {
+            for(int j = 0; j < i; j++) {
+                if(nums[i] > nums[j]) {
+                    dp[i] = Math.max(dp[i], dp[j] + 1);
+                }
+            }
+        }
+        return Arrays.stream(dp)
+                    .max()
+                    .getAsInt() + 1;
+    }
+}
+
+/**
+	이분탐색 활용한 방식
+	nums의 길이 -> N
+	시간 복잡도 : O(NlogN)
+	공간 복잡도 : O(N)
+*/
+class Solution {
+    public int[] list;
+    public int lengthOfLIS(int[] nums) {
+        int result = 0;
+        list =new int[nums.length];
+        Arrays.fill(list, Integer.MAX_VALUE);
+        for(int i = 0; i < list.length; i++) {
+            int idx = binarySearch(list, nums[i]);
+            list[idx] = nums[i];
+            result = Math.max(result, idx + 1);
+
+        }
+        return result;
+    }
+
+    public int binarySearch(int[] list, int target) {
+        int start = 0;
+        int end = list.length - 1;
+
+        while(start <= end) {
+            int mid = (start + end) / 2;
+            if(list[mid] >= target) {
+                end = mid - 1;
+            } else {
+                start = mid + 1;
+            }
+        }
+
+        return start;
+    }
+}
diff --git a/spiral-matrix/se6816.java b/spiral-matrix/se6816.java
new file mode 100644
index 0000000000..7d3a98d139
--- /dev/null
+++ b/spiral-matrix/se6816.java
@@ -0,0 +1,55 @@
+/**
+	구현을 통해 배열을 읽어들이는 방식
+	시간 복잡도 : O(N*M)
+	공간 복잡도 : O(N*M)
+*/
+class Solution {
+    int[] moveY = {1, 0, -1, 0};
+    int[] moveX = {0, -1, 0, 1};
+    int N;
+    int M;
+    public List<Integer> spiralOrder(int[][] matrix) {
+        N = matrix.length;
+        M = matrix[0].length;
+        boolean[][] visited = new boolean[N][M];
+        List<Integer> result = new ArrayList<>();
+        int curX = 0;
+        int curY = 0;
+        int direction = 0;
+        int count = 0;
+        visited[curX][curY] = true;
+        result.add(matrix[curX][curY]);
+
+        while(true) {
+            if(count == 4) {
+                break;
+            }
+            int tempX = curX + moveX[direction];
+            int tempY = curY + moveY[direction];
+            if(outOfIndex(tempX, tempY)) {
+                direction = (direction + 1) % 4;
+                count++;
+                continue;
+            }
+
+            if(visited[tempX][tempY]) {
+               direction = (direction + 1) % 4;
+               count++;
+               continue; 
+            }
+
+            curX = tempX;
+            curY = tempY;
+            result.add(matrix[curX][curY]);
+            visited[curX][curY] = true;
+
+            count = 0;
+        }
+
+        return result;
+    }
+    
+    public boolean outOfIndex(int x, int y) {
+        return x < 0 || x >= N || y < 0 || y >= M;
+    }
+}
diff --git a/valid-parentheses/se6816.java b/valid-parentheses/se6816.java
new file mode 100644
index 0000000000..788d7f473e
--- /dev/null
+++ b/valid-parentheses/se6816.java
@@ -0,0 +1,37 @@
+/**
+	Stack을 활용한 방식
+	문자열 s의 길이 -> N
+	시간 복잡도 : O(N)
+	공간 복잡도 : O(N)
+*/
+class Solution {
+    public boolean isValid(String s) {
+        boolean result= true;
+        Stack<Character> sta=new Stack<>();
+        Map<Character,Character> map=new HashMap<>();
+        map.put('}','{');
+        map.put(']','[');
+        map.put(')','(');
+        for(int i=0; i<s.length();i++){
+            char ch=s.charAt(i);
+            if(ch == '(' || ch == '[' || ch == '{'){
+                sta.push(ch);
+                continue;
+            }
+            char target=map.get(ch);
+            if(sta.isEmpty()){
+                result=false;
+                break;
+            }
+            if(!(sta.peek() == target)){
+                result=false;
+                break;
+            }
+            sta.pop();
+        }
+        if(!sta.isEmpty()){
+            result=false;
+        }
+        return result;    
+    }
+}