From dfe8f0f7e07793c8a65ab2e7df0a260b791fa817 Mon Sep 17 00:00:00 2001
From: jaeyeonjung <87858105+solbijae@users.noreply.github.com>
Date: Mon, 28 Jul 2025 17:12:40 +0900
Subject: [PATCH 1/3] valid-anagram solution

---
 valid-anagram/solbijae.ts | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 valid-anagram/solbijae.ts

diff --git a/valid-anagram/solbijae.ts b/valid-anagram/solbijae.ts
new file mode 100644
index 000000000..8ea6b75f7
--- /dev/null
+++ b/valid-anagram/solbijae.ts
@@ -0,0 +1,17 @@
+function isAnagram(s: string, t: string): boolean {
+    // 첫 시도: 시간 복잡도 O(n log n), 공간 복잡도 O(n)
+    // const sSort = s.split('').sort();
+    // const tSort = t.split('').sort();
+    // return JSON.stringify(sSort) === JSON.stringify(tSort);
+
+    // 시간 복잡도 O(n), 공간복잡도 O(1)
+    if (s.length !== t.length) return false;
+
+    const count = new Array(26).fill(0);
+    for (let i=0; i<s.length; i++) {
+        count[s.charCodeAt(i) - 97]++;
+        count[t.charCodeAt(i) - 97]--;
+    }
+
+    return count.every(c => c === 0);
+};

From 3b62824b0e75256b42f467d9503786b7b1c5694e Mon Sep 17 00:00:00 2001
From: jaeyeonjung <87858105+solbijae@users.noreply.github.com>
Date: Thu, 31 Jul 2025 10:23:29 +0900
Subject: [PATCH 2/3] climbing-stairs solution

---
 climbing-stairs/solbijae.ts | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 climbing-stairs/solbijae.ts

diff --git a/climbing-stairs/solbijae.ts b/climbing-stairs/solbijae.ts
new file mode 100644
index 000000000..c55c52ea0
--- /dev/null
+++ b/climbing-stairs/solbijae.ts
@@ -0,0 +1,16 @@
+function climbStairs(n: number): number {
+    if (n <= 3) return n;
+
+    // 첫 시도: 시간 복잡도 O(2^n), 공간 복잡도 O(n)
+    // return climbStairs(n - 1) + climbStairs(n - 2);
+
+    // 두번째 시도: 시간 복잡도 O(n), 공간 복잡도 O(1)
+    let prev1 = 2, prev2 = 1;
+    for (let i = 3; i <= n; i++) {
+        const curr = prev1 + prev2;
+        prev2 = prev1;
+        prev1 = curr;
+    }
+
+    return prev1;
+};

From 1682c3f95ebd1cb0b273a052f5e46bc61c73d136 Mon Sep 17 00:00:00 2001
From: jaeyeonjung <87858105+solbijae@users.noreply.github.com>
Date: Fri, 1 Aug 2025 15:42:08 +0900
Subject: [PATCH 3/3] product-of-array-except-self

---
 product-of-array-except-self/solbijae.ts | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 product-of-array-except-self/solbijae.ts

diff --git a/product-of-array-except-self/solbijae.ts b/product-of-array-except-self/solbijae.ts
new file mode 100644
index 000000000..60b614b5e
--- /dev/null
+++ b/product-of-array-except-self/solbijae.ts
@@ -0,0 +1,19 @@
+function productExceptSelf(nums: number[]): number[] {
+    // 시간 복잡도: O(n), 공간 복잡도: O(1)
+    const n = nums.length;
+    const answer = new Array(n).fill(1);
+
+    // answer[i]에 left 곱 저장
+    for (let i = 1; i < n; i++) {
+        answer[i] = answer[i - 1] * nums[i - 1];
+    }
+
+    // right 곱을 한 변수에 저장하면서 answer에 곱하기
+    let rightProduct = 1;
+    for (let i = n - 1; i >= 0; i--) {
+        answer[i] *= rightProduct;
+        rightProduct *= nums[i];
+    }
+
+    return answer;
+}