From 6ecb44da9eb7404275f9d8a0b02b15bf2f979e51 Mon Sep 17 00:00:00 2001
From: chae <yce0222@gmail.com>
Date: Mon, 20 Jan 2025 18:21:29 +0900
Subject: [PATCH 1/2] feat: reverse-linked-list solution

---
 reverse-linked-list/YeomChaeeun.ts | 32 ++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 reverse-linked-list/YeomChaeeun.ts

diff --git a/reverse-linked-list/YeomChaeeun.ts b/reverse-linked-list/YeomChaeeun.ts
new file mode 100644
index 000000000..0a4c6ae42
--- /dev/null
+++ b/reverse-linked-list/YeomChaeeun.ts
@@ -0,0 +1,32 @@
+/**
+ * 연결 리스트를 뒤집는 알고리즘
+ * 알고리즘 복잡도
+ * - 시간 복잡도: O(n)
+ * - 공간 복잡도: O(n)
+ */
+/**
+ * Definition for singly-linked list.
+ * class ListNode {
+ *     val: number
+ *     next: ListNode | null
+ *     constructor(val?: number, next?: ListNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.next = (next===undefined ? null : next)
+ *     }
+ * }
+ */
+function reverseList(head: ListNode | null): ListNode | null {
+  // console.log(head)
+  if (head === null || head.next === null) {
+    return head
+  }
+
+  // 마지막 노드에 도달할 때까지 계속 재귀 호출
+  const newHead = reverseList(head.next)
+
+  // 백트래킹 과정
+  head.next.next = head
+  head.next = null
+
+  return newHead
+}

From 10426cfb3d603330b216022bc0a2eca842291a28 Mon Sep 17 00:00:00 2001
From: YeomChaeeun <yce0222@gmail.com>
Date: Sat, 25 Jan 2025 22:18:53 +0900
Subject: [PATCH 2/2] feat: number-of-islands,
 longest-substring-without-repeating-characters solution

---
 .../YeomChaeeun.ts                            | 28 +++++++++++++
 number-of-islands/YeomChaeeun.ts              | 39 +++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 longest-substring-without-repeating-characters/YeomChaeeun.ts
 create mode 100644 number-of-islands/YeomChaeeun.ts

diff --git a/longest-substring-without-repeating-characters/YeomChaeeun.ts b/longest-substring-without-repeating-characters/YeomChaeeun.ts
new file mode 100644
index 000000000..ee3db5108
--- /dev/null
+++ b/longest-substring-without-repeating-characters/YeomChaeeun.ts
@@ -0,0 +1,28 @@
+/**
+ * 중복된 문자가 없는 가장 긴 부분 문자열 구하기
+ * 달레 알고리즘 해설을 참고하여 작성했습니다
+ * 슬라이딩 윈도우 방식 적용
+ * 알고리즘 복잡도
+ * - 시간 복잡도: O(n)
+ * - 공간 복잡도: O(n)
+ * @param s
+ */
+function lengthOfLongestSubstring(s: string): number {
+    const set = new Set<string>();
+    let start = 0;
+    let end = 0;
+    let maxLength = 0;
+
+    while (end < s.length) {
+        if (set.has(s[end])) {
+            set.delete(s[start])
+            start++
+        } else {
+            set.add(s[end])
+            maxLength = Math.max(maxLength, set.size)
+            end++
+        }
+    }
+    return maxLength
+}
+
diff --git a/number-of-islands/YeomChaeeun.ts b/number-of-islands/YeomChaeeun.ts
new file mode 100644
index 000000000..b19695b78
--- /dev/null
+++ b/number-of-islands/YeomChaeeun.ts
@@ -0,0 +1,39 @@
+/**
+ * 2차 배열의 1로된 섬 구하기
+ * 달레 알고리즘 해석을 참고하여 작성했습니다.
+ * DFS(깊이 우선 알고리즘)
+ * 알고리즘 복잡도
+ * - 시간 복잡도: O(m x n)
+ * - 공간 복잡도: O(m x n)
+ * @param grid
+ */
+function numIslands(grid: string[][]): number {
+    const rows = grid.length
+    const cols = grid[0].length
+    let islands = 0
+
+    // 인접한 땅의 1을 찾아야 함 - 상하좌우
+    const dfs = (i: number, j: number): void => {
+        if (i < 0 || i >= rows || j < 0 || j >= cols || grid[i][j] !== '1') {
+            return
+        }
+
+        grid[i][j] = '0' // 한번 확인한 경우 물로 바꿔줌
+
+        dfs(i + 1, j)
+        dfs(i - 1, j)
+        dfs(i, j + 1)
+        dfs(i, j - 1)
+    }
+
+    for (let i = 0; i < rows; i++) {
+        for (let j = 0; j < cols; j++) {
+            if (grid[i][j] === '1') {
+                dfs(i, j)
+                islands++
+            }
+        }
+    }
+
+    return islands
+}