From 686fb84ef832b497e0cf94a5030046bb4cd0a136 Mon Sep 17 00:00:00 2001
From: songyc macbook <gitea@gitea>
Date: Fri, 2 Jan 2026 21:41:59 +0900
Subject: [PATCH] baekjoon 20260102

---
 code_study/Baekjoon/swift/10156.swift | 10 +++++
 code_study/Baekjoon/swift/9466.swift  | 55 +++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 code_study/Baekjoon/swift/10156.swift
 create mode 100644 code_study/Baekjoon/swift/9466.swift

diff --git a/code_study/Baekjoon/swift/10156.swift b/code_study/Baekjoon/swift/10156.swift
new file mode 100644
index 0000000..6a15591
--- /dev/null
+++ b/code_study/Baekjoon/swift/10156.swift
@@ -0,0 +1,10 @@
+func sol() -> Int {
+    guard let input = readLine() else { return 0 }
+    let info = input.split(separator: " ").compactMap{Int($0)}
+    
+    let ans = { (a: Int, b: Int) -> Int in return a - b > 0 ? a - b : 0 }
+    
+    return ans(info[0]*info[1], info[2])
+}
+
+print(sol())
\ No newline at end of file
diff --git a/code_study/Baekjoon/swift/9466.swift b/code_study/Baekjoon/swift/9466.swift
new file mode 100644
index 0000000..d89297c
--- /dev/null
+++ b/code_study/Baekjoon/swift/9466.swift
@@ -0,0 +1,55 @@
+func solve() -> Int {
+    guard let n = Int(readLine() ?? ""),
+          let input = readLine()
+    else { return 0 }
+    
+    let choice: [Int] = [0] + input.split(separator: " ").compactMap({Int($0)})
+    var visited: [Bool] = Array(repeating: false, count: n+1)
+    var done: [Bool] = Array(repeating: false, count: n+1)
+    var cnt: Int = 0
+    
+    for i in 1...n {
+        if i == choice[i] {
+            cnt += 1
+            visited[i] = true
+            done[i] = true
+        }
+    }
+    
+    func dfs(_ current: Int) {
+        visited[current] = true
+        let next = choice[current]
+        
+        if !visited[next] {
+            dfs(next)
+        }
+        else if !done[next] {
+            cnt += 1
+            var n = next
+            while n != current {
+                cnt += 1
+                n = choice[n]
+            }
+        }
+        
+        done[current] = true
+    }
+    
+    for i in 1...n {
+        if !done[i] {
+            dfs(i)
+        }
+    }
+    
+    return n-cnt
+}
+
+var ans: [Int] = []
+
+if let T = Int(readLine() ?? "") {
+    for _ in  0..<T {
+        ans.append(solve())
+    }
+}
+
+print(ans.compactMap({String($0)}).joined(separator: "\n"))