diff --git a/container-with-most-water/YuuuuuuYu.java b/container-with-most-water/YuuuuuuYu.java
new file mode 100644
index 000000000..5be822bab
--- /dev/null
+++ b/container-with-most-water/YuuuuuuYu.java
@@ -0,0 +1,40 @@
+/**
+ * Runtime: 3ms
+ * Time Complexity: O(n)
+ *
+ * Memory: 77.24MB
+ * Space Complexity: O(1)
+ *
+ * Approach: 좌우 높이 중 더 작은 높이 기준으로 계산하기 때문에 그 높이를 최대한 높일 수 있는 방향으로 포인터 이동
+ * - while문 내에서 현재 포인터의 높이보다 같거나 작은 높이를 건너뛰도록 최적화
+ */
+class Solution {
+    public int maxArea(int[] height) {
+        int left = 0;
+        int right = height.length-1;
+        int max = 0;
+
+        while (left < right) {
+            int hLeft = height[left];
+            int hRight = height[right];
+            int currentArea = (right-left) * Math.min(hLeft, hRight);
+            if (currentArea > max) {
+                max = currentArea;
+            }
+
+            if (hLeft < hRight) {
+                left++;
+                while (left < right && height[left] <= hLeft) {
+                    left++;
+                }
+            } else {
+                right--;
+                while (left < right && height[right] <= hRight) {
+                    right--;
+                }
+            }
+        }
+
+        return max;
+    }
+}
diff --git a/longest-increasing-subsequence/YuuuuuuYu.java b/longest-increasing-subsequence/YuuuuuuYu.java
new file mode 100644
index 000000000..853218d91
--- /dev/null
+++ b/longest-increasing-subsequence/YuuuuuuYu.java
@@ -0,0 +1,40 @@
+/**
+ * Runtime: 3ms
+ * Time Complexity: O(n log n)
+ * - 각 요소마다 이분 탐색
+ *
+ * Memory: 45.99MB
+ * Space Complexity: O(n)
+ *
+ * Approach: Patience Sorting, 각 원소를 순서대로 확인하며 현재까지 만든 가장 유리한 수열 계산
+ * - result의 모든 원소보다 크면 맨 뒤에 추가
+ * - 그렇지 않으면, 이분 탐색으로 나온 위치에 값을 대체
+ */
+class Solution {
+    public int lengthOfLIS(int[] nums) {
+        int[] result = new int[nums.length];
+        int resultSize = 0;
+
+        for (int num : nums) {
+            int left = 0;
+            int right = resultSize;
+
+            while (left < right) {
+                int mid = left + (right-left) / 2;
+                if (result[mid] < num) {
+                    left = mid+1;
+                } else {
+                    right = mid;
+                }
+            }
+
+            result[left] = num;
+
+            if (left == resultSize) {
+                resultSize++;
+            }
+        }
+
+        return resultSize;
+    }
+}
diff --git a/valid-parentheses/YuuuuuuYu.java b/valid-parentheses/YuuuuuuYu.java
new file mode 100644
index 000000000..3021f1ede
--- /dev/null
+++ b/valid-parentheses/YuuuuuuYu.java
@@ -0,0 +1,33 @@
+/**
+ * Runtime: 4ms
+ * Time Complexity: O(n)
+ *
+ * Memory: 42.94MB
+ * Space Complexity: O(n)
+ *
+ * Approach: 스택 사용
+ * - 열린 괄호를 푸시하면서 닫힌 괄호가 나올 때마다 스택에서 팝하여 짝이 맞는지 확인
+ */
+class Solution {
+    public boolean isValid(String s) {
+        if (s.length()%2 == 1) return false;
+
+        Stack<Character> stack = new Stack<>();
+        Map<Character, Character> map = new HashMap<>();
+        map.put('(', ')');
+        map.put('{', '}');
+        map.put('[', ']');
+
+        for (char ch: s.toCharArray()) {
+            if (map.containsKey(ch)) {
+                stack.push(ch);
+            } else if (")}]".indexOf(ch) != -1) {
+                if (stack.isEmpty() || ch != map.get(stack.pop())) {
+                    return false;
+                }
+            }
+        }
+
+        return stack.isEmpty();
+    }
+}