From 34258fadd551b06b31abaeb0b13b020dee478931 Mon Sep 17 00:00:00 2001
From: hyejj19 <hyejj19@naver.com>
Date: Mon, 30 Mar 2026 11:00:59 +0900
Subject: [PATCH 1/3] solve best-time-to-buy-and-sell-stock

---
 best-time-to-buy-and-sell-stock/hyejj19.ts | 26 ++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 best-time-to-buy-and-sell-stock/hyejj19.ts

diff --git a/best-time-to-buy-and-sell-stock/hyejj19.ts b/best-time-to-buy-and-sell-stock/hyejj19.ts
new file mode 100644
index 0000000000..9c66553811
--- /dev/null
+++ b/best-time-to-buy-and-sell-stock/hyejj19.ts
@@ -0,0 +1,26 @@
+function maxProfit(prices: number[]): number {
+  let minPrice = Number.MAX_SAFE_INTEGER;
+  let maxProfit = 0;
+
+  for (let p of prices) {
+    if (minPrice >= p) {
+      minPrice = p;
+      continue;
+    } else {
+      let profit = p - minPrice;
+      if (profit > maxProfit) maxProfit = profit;
+    }
+  }
+  return maxProfit;
+}
+
+function maxProfit(prices: number[]): number {
+  let minPrice = Infinity;
+  let maxProfit = 0;
+
+  for (let p of prices) {
+    minPrice = Math.min(minPrice, p);
+    maxProfit = Math.max(maxProfit, p - minPrice);
+  }
+  return maxProfit;
+}

From fcf4286851c32150a4662cbd0a25fd4415061da1 Mon Sep 17 00:00:00 2001
From: hyejj19 <hyejj19@naver.com>
Date: Wed, 8 Apr 2026 14:54:49 +0900
Subject: [PATCH 2/3] solve valid-parentheses

---
 valid-parentheses/hyejj19.ts | 56 ++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 valid-parentheses/hyejj19.ts

diff --git a/valid-parentheses/hyejj19.ts b/valid-parentheses/hyejj19.ts
new file mode 100644
index 0000000000..49a6f5f574
--- /dev/null
+++ b/valid-parentheses/hyejj19.ts
@@ -0,0 +1,56 @@
+function isValid(s: string): boolean {
+  const stack = [];
+  const open = '([{';
+  for (const v of s) {
+    if (open.includes(v)) {
+      stack.push(v);
+    } else {
+      if (
+        (v === ')' && stack.at(-1) === '(') ||
+        (v === '}' && stack.at(-1) === '{') ||
+        (v === ']' && stack.at(-1) === '[')
+      ) {
+        // 일치하는 닫는 괄호라면 pop
+        stack.pop();
+      } else {
+        // 일치하지 않는 닫는 괄호라면 false
+        return false;
+      }
+    }
+  }
+
+  return stack.length === 0 ? true : false;
+}
+
+function isValid(s: string): boolean {
+  const pairs = new Map([
+    [')', '('],
+    ['}', '{'],
+    [']', '['],
+  ]);
+  const stack = [];
+
+  for (const v of s) {
+    // v 가 닫는 괄호이면
+    if (pairs.has(v)) {
+      if (pairs.get(v) === stack.at(-1)) {
+        // 일치하는 닫는 괄호라면 pop
+        stack.pop();
+      } else {
+        // 일치하지 않는 닫는 괄호라면 false
+        return false;
+      }
+    } else {
+      // 여는 괄호이면
+      stack.push(v);
+    }
+  }
+
+  return stack.length === 0;
+}
+
+/*
+1. 여는 괄호에 해당한다 -> 스택에 push
+2. 닫는 괄호가 나왔다 -> 스택의 top과 일치하면 pop 아니라면 false
+3. 스택이 비어있다 -> true
+ */

From bed992d1d5668921009db26102c66071b28a6813 Mon Sep 17 00:00:00 2001
From: hyejj19 <hyejj19@naver.com>
Date: Wed, 8 Apr 2026 15:27:16 +0900
Subject: [PATCH 3/3] solve container-with-most-water

---
 container-with-most-water/hyejj19.ts | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 container-with-most-water/hyejj19.ts

diff --git a/container-with-most-water/hyejj19.ts b/container-with-most-water/hyejj19.ts
new file mode 100644
index 0000000000..769c4e6710
--- /dev/null
+++ b/container-with-most-water/hyejj19.ts
@@ -0,0 +1,23 @@
+function maxArea(height: number[]): number {
+  let left = 0;
+  let right = height.length - 1;
+  let max = -1;
+
+  while (right > left) {
+    const v = Math.min(height[left], height[right]) * (right - left);
+    max = Math.max(max, v);
+    if (height[left] >= height[right]) {
+      right--;
+    } else {
+      left++;
+    }
+  }
+  return max;
+}
+
+/*
+1. Math.min(height[left], height[right]) * (right - left);
+2. left 와 right 를 양 끝에서 가리킴
+3. 너비를 계산해서 max 값을 갱신하고, 둘 중 더 짧은 쪽을 안쪽으로 이동
+4. left 와 right 가 만나면 종료
+ */