diff --git a/container-with-most-water/jdy8739.js b/container-with-most-water/jdy8739.js
new file mode 100644
index 000000000..2e6935370
--- /dev/null
+++ b/container-with-most-water/jdy8739.js
@@ -0,0 +1,32 @@
+/**
+ * @param {number[]} height
+ * @return {number}
+ */
+var maxArea = function(height) {
+    let max = 0;
+
+    let startIdx = 0;
+    let endIdx = height.length - 1;
+
+    while (startIdx < endIdx) {
+        const start = height[startIdx];
+        const end = height[endIdx];
+
+        const gap = endIdx - startIdx;
+        const min = Math.min(start, end);
+
+        const area = gap * min;
+
+        max = Math.max(max, area);
+
+        if (start < end) startIdx++;
+        else endIdx--;
+    }
+
+    return max;
+};
+
+// 시간복잡도 O(n)
+// n은 주어진 배열(height)의 길이
+
+
diff --git a/spiral-matrix/jdy8739.js b/spiral-matrix/jdy8739.js
new file mode 100644
index 000000000..136bb348c
--- /dev/null
+++ b/spiral-matrix/jdy8739.js
@@ -0,0 +1,49 @@
+/**
+ * @param {number[][]} matrix
+ * @return {number[]}
+ */
+var spiralOrder = function(matrix) {
+    let top = 0;
+    let left = 0;
+    let bottom = matrix.length - 1;
+    let right = matrix[0].length - 1;
+
+    const answer = [];
+
+    while (top <= bottom && left <= right) {
+        for (let i = left; i <= right; i++) {
+            answer.push(matrix[top][i]);
+        }
+        top++;
+
+        if (top > bottom) {
+            break;
+        }
+
+        for (let j = top; j <= bottom; j++) {
+            answer.push(matrix[j][right]);
+        }
+        right--;
+
+        if (left > right) {
+            break;
+        }
+
+        for (let k = right; k >= left; k--) {
+            answer.push(matrix[bottom][k]);
+        }
+        bottom--;
+
+        for (let l = bottom; l >= top; l--) {
+            answer.push(matrix[l][left]);
+        }
+        left++;
+    }
+
+    return answer;
+};
+
+// 시간 복잡도 O(m * n)
+// 공간 복잡도 O(1)
+
+
diff --git a/valid-parentheses/jdy8739.js b/valid-parentheses/jdy8739.js
new file mode 100644
index 000000000..194fbc83f
--- /dev/null
+++ b/valid-parentheses/jdy8739.js
@@ -0,0 +1,30 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+var isValid = function(s) {
+    const stack = [];
+
+    for (let i=0; i<s.length; i++) {
+        const cur = s[i];
+
+        if (cur === '(' || cur === '[' || cur === '{') {
+            stack.push(cur);
+        } else {
+            const topOfStack = stack[stack.length - 1];
+
+            const caseA = topOfStack === '(' && cur === ')';
+            const caseB = topOfStack === '[' && cur === ']';
+            const caseC = topOfStack === '{' && cur === '}';
+
+            if (caseA || caseB || caseC) {
+                stack.pop();
+            } else {
+                return false;
+            }
+        }
+    }
+
+    return stack.length === 0;
+};
+