From 9b2ab2d34ba61c828775d688dd7e86d329f304a1 Mon Sep 17 00:00:00 2001
From: delight010 <seonga.oh00@gmail.com>
Date: Thu, 25 Sep 2025 20:47:04 +0900
Subject: [PATCH 1/2] solve problem

---
 invert-binary-tree/delight010.swift | 41 +++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 invert-binary-tree/delight010.swift

diff --git a/invert-binary-tree/delight010.swift b/invert-binary-tree/delight010.swift
new file mode 100644
index 000000000..fef9cd63d
--- /dev/null
+++ b/invert-binary-tree/delight010.swift
@@ -0,0 +1,41 @@
+public class TreeNode {
+    public var val: Int
+    public var left: TreeNode?
+    public var right: TreeNode?
+    public init() { self.val = 0; self.left = nil; self.right = nil; }
+    public init( val: Int) { self.val = val; self.left = nil; self.right = nil; }
+    public init( val: Int, * left: TreeNode?, * right: TreeNode?) {
+        self.val = val
+        self.left = left
+        self.right = right
+    }
+}
+
+class Solution {
+    // Time O(n)
+    // Space O(n)
+    func invertTree(_ root: TreeNode?) -> TreeNode? {
+        guard let root = root else {
+            return nil
+        }
+
+        var queue: [TreeNode] = [root]
+
+        while queue.isEmpty == false {
+            let current = queue.removeFirst()
+
+            if let left = current.left {
+                queue.append(left)
+            }
+
+            if let right = current.right {
+                queue.append(right)
+            }
+
+            (current.left, current.right) = (current.right, current.left)
+        }
+
+        return root
+    }
+}
+ 

From 138d4bbc50cff23bc39a04318cc36627411cc356 Mon Sep 17 00:00:00 2001
From: delight010 <seonga.oh00@gmail.com>
Date: Fri, 26 Sep 2025 19:59:02 +0900
Subject: [PATCH 2/2] solve problem

---
 course-schedule/delight010.swift | 38 ++++++++++++++++++++++++++++++++
 jump-game/delight010.swift       | 16 ++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 course-schedule/delight010.swift
 create mode 100644 jump-game/delight010.swift

diff --git a/course-schedule/delight010.swift b/course-schedule/delight010.swift
new file mode 100644
index 000000000..6afa0b053
--- /dev/null
+++ b/course-schedule/delight010.swift
@@ -0,0 +1,38 @@
+class Solution {
+    // Time  O(V + E)
+    // Space  O(V + E)
+    func canFinish(_ numCourses: Int, _ prerequisites: [[Int]]) -> Bool {
+        var indegree: [Int] = Array(repeating: 0, count: numCourses)
+        var queue: [Int] = []
+        var graph: [[Int]] = Array(repeating: [], count: numCourses)
+        
+        for i in 0..<prerequisites.count {
+            let degree = prerequisites[i].first!
+            let graphIndex = prerequisites[i][1]
+            indegree[degree] += 1
+            graph[graphIndex].append(degree)
+        }
+        
+        for i in 0..<indegree.count {
+            if indegree[i] == 0 {
+                queue.append(i)
+            }
+        }
+        
+        var count = 0
+        
+        while !queue.isEmpty {
+            let current = queue.removeFirst()
+            count += 1
+            for i in graph[current] {
+                indegree[i] -= 1
+                if indegree[i] == 0 {
+                    queue.append(i)
+                }
+            }
+        }
+        
+        return count == numCourses
+    }
+}
+ 
diff --git a/jump-game/delight010.swift b/jump-game/delight010.swift
new file mode 100644
index 000000000..998dec799
--- /dev/null
+++ b/jump-game/delight010.swift
@@ -0,0 +1,16 @@
+class Solution {
+    // Time O(n)
+    // Space O(1)
+    func canJump(_ nums: [Int]) -> Bool {
+        var maxReachIndex = 0
+        for i in 0..<nums.count {
+            if i > maxReachIndex {
+                return false
+            }
+            maxReachIndex = max(maxReachIndex, nums[i] + i)
+        }
+        
+        return maxReachIndex >= nums.count - 1
+    }
+}
+