From f530361b18116966ee10f01b6e3a9b7187dfa764 Mon Sep 17 00:00:00 2001
From: songyc macbook <gitea@gitea>
Date: Wed, 8 Apr 2026 14:40:09 +0900
Subject: [PATCH] baekjoon 20260408

---
 code_study/Baekjoon/python/4504.py    |  5 ++
 code_study/Baekjoon/swift/20303.swift | 91 +++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 code_study/Baekjoon/python/4504.py
 create mode 100644 code_study/Baekjoon/swift/20303.swift

diff --git a/code_study/Baekjoon/python/4504.py b/code_study/Baekjoon/python/4504.py
new file mode 100644
index 0000000..3751184
--- /dev/null
+++ b/code_study/Baekjoon/python/4504.py
@@ -0,0 +1,5 @@
+res = []
+n = int(input())
+while (m := int(input())) != 0 :
+    res.append(f"{m} is NOT a multiple of {n}." if m%n else f"{m} is a multiple of {n}.")
+print("\n".join(res))
\ No newline at end of file
diff --git a/code_study/Baekjoon/swift/20303.swift b/code_study/Baekjoon/swift/20303.swift
new file mode 100644
index 0000000..b76b2de
--- /dev/null
+++ b/code_study/Baekjoon/swift/20303.swift
@@ -0,0 +1,91 @@
+import Foundation
+
+final class FileIO {
+    private let buffer:[UInt8]
+    private var index: Int = 0
+
+    init(fileHandle: FileHandle = FileHandle.standardInput) {
+        
+        buffer = Array(try! fileHandle.readToEnd()!) + [UInt8(0)] // 인덱스 범위 초과 방지
+    }
+
+    @inline(__always) private func read() -> UInt8 {
+        defer { index += 1 }
+        return buffer[index]
+    }
+
+    @inline(__always) func readInt() -> Int {
+        var sum = 0
+        var now = read()
+        var isPositive = true
+
+        while now == 10 || now == 32 { now = read() } // 공백과 줄바꿈 무시
+        if now == 45 { isPositive = false; now = read() } // 음수 처리
+
+        while now >= 48, now <= 57 {
+            sum = sum * 10 + Int(now-48)
+            now = read()
+        }
+
+        return sum * (isPositive ? 1 : -1)
+    }
+}
+
+func main() {
+    let fp = FileIO()
+    
+    let N = fp.readInt(), M = fp.readInt(), K = fp.readInt()
+    var candy: [Int] = [0]
+    for _ in 1...N {
+        candy.append(fp.readInt())
+    }
+    
+    var roots: [Int] = (0...N).map{Int($0)}
+    var rank: [Int] = Array(repeating: 0, count: N+1)
+    
+    func find(_ x: Int) -> Int {
+        if x != roots[x] { roots[x] = find(roots[x]) }
+        return roots[x]
+    }
+    
+    func union(_ x: Int, _ y: Int) {
+        var a = find(x), b = find(y)
+        
+        if a == b { return }
+        
+        if rank[a] < rank[b] { swap(&a, &b) }
+        
+        roots[b] = a
+        
+        if rank[a] == rank[b] { rank[a] += 1 }
+    }
+    
+    for _ in 0..<M { union(fp.readInt(), fp.readInt()) }
+    
+    var counter: [Int: Int] = [:]
+    for n in 1...N {
+        let r = find(n)
+        counter[r] = (counter[r] ?? 0) + 1
+        if n == r { continue }
+        candy[r] += candy[n]
+    }
+    
+    var pair: [(nums: Int, total_candy: Int)] = []
+    
+    for (group, nums) in counter {
+        pair.append((nums: nums, total_candy: candy[group]))
+    }
+    
+    var dp: [Int] = Array(repeating: 0, count: K)
+    for i in 0..<pair.count {
+        let k = pair[i].nums, c = pair[i].total_candy
+        
+        for j in stride(from: K-1, through: k, by: -1) {
+            dp[j] = max(dp[j], dp[j-k] + c)
+        }
+    }
+    
+    print(dp[K-1])
+}
+
+main()