From c2e782b8b908687cc92957f459744dd34e85d42a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EB=91=90=EB=A6=AC?= <kdle_@naver.com>
Date: Thu, 15 May 2025 10:59:57 +0900
Subject: [PATCH 1/5] Solution Reverse linked list

---
 reverse-linked-list/doitduri.swift | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
 create mode 100644 reverse-linked-list/doitduri.swift

diff --git a/reverse-linked-list/doitduri.swift b/reverse-linked-list/doitduri.swift
new file mode 100644
index 000000000..46ad6036e
--- /dev/null
+++ b/reverse-linked-list/doitduri.swift
@@ -0,0 +1,14 @@
+class Solution {
+    func reverseList(_ head: ListNode?) -> ListNode? {
+        var current = head, previous: ListNode? = nil
+
+        while current != nil {
+            let next = current?.next
+            current?.next = previous
+            previous = current
+            current = next
+        }
+
+        return previous
+    }
+}

From cfd3c2c8740e47ab818037b31eb083a9a3b2ab2c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EB=91=90=EB=A6=AC?= <kdle_@naver.com>
Date: Fri, 16 May 2025 14:02:59 +0900
Subject: [PATCH 2/5] Solution Longest substring without repeating characters

---
 .../doitduri.swift                            | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 longest-substring-without-repeating-characters/doitduri.swift

diff --git a/longest-substring-without-repeating-characters/doitduri.swift b/longest-substring-without-repeating-characters/doitduri.swift
new file mode 100644
index 000000000..9351d3af0
--- /dev/null
+++ b/longest-substring-without-repeating-characters/doitduri.swift
@@ -0,0 +1,20 @@
+class Solution {
+    func lengthOfLongestSubstring(_ s: String) -> Int {
+        var charIndexMap = [Character: Int]()
+        var maxLength = 0
+        var startIndex = 0
+        
+        for (i, char) in Array(s).enumerated() {
+            if let lastIndex = charIndexMap[char], lastIndex >= startIndex {
+                startIndex = lastIndex + 1
+            }
+            
+            let currentLength = i - startIndex + 1
+            maxLength = max(maxLength, currentLength)
+            
+            charIndexMap[char] = i
+        }
+        
+        return maxLength
+    }
+}

From 1c022352a86fb7d5dbbc34c0506d993e3293753f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EB=91=90=EB=A6=AC?= <kdle_@naver.com>
Date: Fri, 16 May 2025 14:52:02 +0900
Subject: [PATCH 3/5] Solution Number of islands

---
 number-of-islands/doitduri.swift | 34 ++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 number-of-islands/doitduri.swift

diff --git a/number-of-islands/doitduri.swift b/number-of-islands/doitduri.swift
new file mode 100644
index 000000000..fbefd2ecb
--- /dev/null
+++ b/number-of-islands/doitduri.swift
@@ -0,0 +1,34 @@
+class Solution {
+    func numIslands(_ grid: [[Character]]) -> Int {
+        guard !grid.isEmpty else { return 0 }
+        
+        let rows = grid.count
+        let colums = grid[0].count
+        var visited = grid
+        var islandCount = 0
+        
+        func dfs(_ row: Int, _ col: Int) {
+            guard row >= 0 && row < rows && col >= 0 && col < colums && visited[row][col] == "1" else {
+                return
+            }
+            
+            visited[row][col] = "0"
+            
+            dfs(row - 1, col)
+            dfs(row + 1, col)
+            dfs(row, col - 1)
+            dfs(row, col + 1)
+        }
+        
+        for row in 0..<rows {
+            for col in 0..<colums {
+                if visited[row][col] == "1" {
+                    islandCount += 1
+                    dfs(row, col)
+                }
+            }
+        }
+        
+        return islandCount
+    }
+}

From 32faa564866702df2ff4d56bf2ef78859d97c93f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EB=91=90=EB=A6=AC?= <kdle_@naver.com>
Date: Sat, 17 May 2025 20:53:03 +0900
Subject: [PATCH 4/5] Solution Unique paths

---
 unique-paths/doitduri.swift | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 unique-paths/doitduri.swift

diff --git a/unique-paths/doitduri.swift b/unique-paths/doitduri.swift
new file mode 100644
index 000000000..4437894eb
--- /dev/null
+++ b/unique-paths/doitduri.swift
@@ -0,0 +1,21 @@
+class Solution {
+    func uniquePaths(_ m: Int, _ n: Int) -> Int {
+        var dp = Array(repeating: Array(repeating: 0, count: n), count: m)
+        
+        for j in 0..<n {
+            dp[0][j] = 1
+        }
+        
+        for i in 0..<m {
+            dp[i][0] = 1
+        }
+        
+        for i in 1..<m {
+            for j in 1..<n {
+                dp[i][j] = dp[i-1][j] + dp[i][j-1]
+            }
+        }
+        
+        return dp[m-1][n-1]
+    }
+}

From 474f3d589eb393f1d166c85b8086987eed31ce5c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EB=91=90=EB=A6=AC?= <kdle_@naver.com>
Date: Sat, 17 May 2025 21:52:22 +0900
Subject: [PATCH 5/5] Solution Set matrix zeroes

---
 set-matrix-zeroes/doitduri.swift | 60 ++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 set-matrix-zeroes/doitduri.swift

diff --git a/set-matrix-zeroes/doitduri.swift b/set-matrix-zeroes/doitduri.swift
new file mode 100644
index 000000000..ba441cd12
--- /dev/null
+++ b/set-matrix-zeroes/doitduri.swift
@@ -0,0 +1,60 @@
+class Solution {
+    func setZeroes(_ matrix: inout [[Int]]) {
+    let m = matrix.count
+    let n = matrix[0].count
+    
+    var firstRowHasZero = false
+    var firstColHasZero = false
+    
+    for i in 0..<m {
+        if matrix[i][0] == 0 {
+            firstColHasZero = true
+            break
+        }
+    }
+    
+    for j in 0..<n {
+        if matrix[0][j] == 0 {
+            firstRowHasZero = true
+            break
+        }
+    }
+    
+    for i in 1..<m {
+        for j in 1..<n {
+            if matrix[i][j] == 0 {
+                matrix[i][0] = 0
+                matrix[0][j] = 0
+            }
+        }
+    }
+    
+    for i in 1..<m {
+        if matrix[i][0] == 0 {
+            for j in 1..<n {
+                matrix[i][j] = 0
+            }
+        }
+    }
+    
+    for j in 1..<n {
+        if matrix[0][j] == 0 {
+            for i in 1..<m {
+                matrix[i][j] = 0
+            }
+        }
+    }
+    
+    if firstRowHasZero {
+        for j in 0..<n {
+            matrix[0][j] = 0
+        }
+    }
+    
+    if firstColHasZero {
+        for i in 0..<m {
+            matrix[i][0] = 0
+        }
+    }
+    }
+}