diff --git a/container-with-most-water/sonjh1217.swift b/container-with-most-water/sonjh1217.swift
new file mode 100644
index 000000000..668568c96
--- /dev/null
+++ b/container-with-most-water/sonjh1217.swift
@@ -0,0 +1,27 @@
+class Solution {
+    func maxArea(_ height: [Int]) -> Int {
+        var heights = height
+        var start = 0
+        var end = heights.count - 1
+        var maxAmount = 0
+
+        while start < end {
+            let startHeight = heights[start]
+            let endHeight = heights[end]
+            let amount = min(startHeight, endHeight) * (end - start)
+            maxAmount = max(amount, maxAmount)
+
+            if startHeight < endHeight {
+                start += 1
+            } else {
+                end -= 1
+            }
+        }
+
+        return maxAmount
+
+        //시간 O(n)
+        //공간 O(1)
+    }
+}
+
diff --git a/design-add-and-search-words-data-structure/sonjh1217.swift b/design-add-and-search-words-data-structure/sonjh1217.swift
new file mode 100644
index 000000000..2d01724d5
--- /dev/null
+++ b/design-add-and-search-words-data-structure/sonjh1217.swift
@@ -0,0 +1,55 @@
+class WordDictionary {
+    class TrieNode {
+        var children: [Character: TrieNode] = [:]
+        var isEndOfWord = false
+    }
+    
+    private var root: TrieNode
+
+    init() {
+        root = TrieNode()
+    }
+    
+    // O(n) time / O(n) space
+    func addWord(_ word: String) {
+        var node = root
+        
+        for character in word {
+            if node.children[character] == nil {
+                node.children[character] = TrieNode()
+            }
+            
+            node = node.children[character]!
+        }
+        
+        node.isEndOfWord = true
+    }
+    
+    // O(m) ~ O(26^m) time / O(m) space
+    func search(_ word: String) -> Bool {
+        return dfs(word: Array(word), index: 0, node: root)
+    }
+    
+    private func dfs(word: [Character], index: Int, node: TrieNode) -> Bool {
+        if index == word.count {
+            return node.isEndOfWord
+        }
+        
+        let character = word[index]
+        
+        if character == "." {
+            for child in node.children.values {
+                if dfs(word: word, index: index + 1, node: child) {
+                    return true
+                }
+            }
+            return false
+        } else {
+            guard let child = node.children[character] else {
+                return false
+            }
+            return dfs(word: word, index: index + 1, node: child)
+        }
+    }
+}
+
diff --git a/group-anagrams/sonjh1217.swift b/group-anagrams/sonjh1217.swift
index 7682acb6e..6d5d763af 100644
--- a/group-anagrams/sonjh1217.swift
+++ b/group-anagrams/sonjh1217.swift
@@ -2,7 +2,7 @@ class Solution {
     func groupAnagrams(_ strs: [String]) -> [[String]] {
         var stringsByCount = [[Int]: [String]]()
         
-        strs.map { str in
+        strs.forEach { str in
             var countsByAlphabet = Array(repeating: 0, count: 26)
             for char in str.unicodeScalars {
                 countsByAlphabet[Int(char.value) - 97] += 1
diff --git a/longest-increasing-subsequence/sonjh1217.swift b/longest-increasing-subsequence/sonjh1217.swift
new file mode 100644
index 000000000..e20fa67c1
--- /dev/null
+++ b/longest-increasing-subsequence/sonjh1217.swift
@@ -0,0 +1,41 @@
+class Solution {
+    // O(nlogn) time / O(n) space
+    func lengthOfLIS(_ nums: [Int]) -> Int {
+        var piles: [Int] = []
+        // Patience(1인 카드놀이) sort 이용
+        for num in nums {
+            let leftInsertion = binarySearch(piles: piles, target: num)
+
+            // piles[k] >= x인 pile이 없을 때만 append(길이 증가)
+            if leftInsertion == piles.count {
+                piles.append(num)
+            } else {
+                //가장 왼쪽의 piles[k] >= x 위치에 교체
+                piles[leftInsertion] = num
+            }
+
+        }
+        
+        // piles[k] = 길이 (k+1) 증가수열이 가질 수 있는 '끝값의 최소치'
+        // sort 로직상 piles.count가 최대한 길게 만들었기 때문에 piles.count는 가장 긴 길이가 됨
+        return piles.count
+    }
+
+    func binarySearch(piles: [Int], target: Int) -> Int {
+        var left = 0
+        
+        //target의 삽입 위치고 맨 끝에 덧붙일수도 있어서 nums.count - 1 이 아님
+        var right = piles.count
+
+        while left < right {
+            let mid = left + (right - left) / 2
+            if target > piles[mid] {
+                left = mid + 1
+            } else {
+                //맨 왼쪽 거를 찾아야 함으로 다시 쪼개가면서 맨 왼쪽 거를 찾는다. 맨 왼쪽 거에 넣어야 길이(k) 증가수열의 끝값이 가장 작게 된다. 이래야 최대한 뒤에 계속 더 이어붙여서 최대한 길게 piles를 만들 수 있음.
+                right = mid
+            }
+        }
+        return left
+    }
+}
diff --git a/valid-parentheses/sonjh1217.swift b/valid-parentheses/sonjh1217.swift
new file mode 100644
index 000000000..05ef347f2
--- /dev/null
+++ b/valid-parentheses/sonjh1217.swift
@@ -0,0 +1,22 @@
+class Solution {
+    func isValid (_ s: String) -> Bool {
+        var brackets: [Character: Character] = ["(": ")", "[": "]", "{": "}"]
+        var closers = [Character]()
+        
+        for character in s {
+            if let closer = brackets[character] {
+                closers.append(closer)
+            } else if character == closers.last {
+                closers.removeLast()
+            } else {
+                return false
+            }
+        }
+        
+        return closers.isEmpty
+        
+        //시간 O(n) (string의 길이)
+        //공간 O(n)
+    }
+}
+