From 11133ac996a0a9680276ede63069a3a29456859b Mon Sep 17 00:00:00 2001 From: Ukj0ng <90972240+Ukj0ng@users.noreply.github.com> Date: Tue, 18 Nov 2025 22:14:54 +0900 Subject: [PATCH] =?UTF-8?q?[20251118]=20BOJ=20/=20G5=20/=20=ED=8A=B8?= =?UTF-8?q?=EB=A6=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../18 BOJ G5 \355\212\270\353\246\254.md" | 70 +++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 "Ukj0ng/202511/18 BOJ G5 \355\212\270\353\246\254.md" diff --git "a/Ukj0ng/202511/18 BOJ G5 \355\212\270\353\246\254.md" "b/Ukj0ng/202511/18 BOJ G5 \355\212\270\353\246\254.md" new file mode 100644 index 00000000..509e22b9 --- /dev/null +++ "b/Ukj0ng/202511/18 BOJ G5 \355\212\270\353\246\254.md" @@ -0,0 +1,70 @@ +``` +import java.io.*; +import java.util.*; + +public class Main { + private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); + private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); + private static List[] edges; + private static int[] parent; + private static int N, M, answer; + public static void main(String[] args) throws IOException { + init(); + + for (int i = 0; i < N; i++) { + if (parent[i] == -1 && i != M) { + DFS(i); + } + } + + bw.write(answer + "\n"); + bw.flush(); + bw.close(); + br.close(); + } + + private static void init() throws IOException { + N = Integer.parseInt(br.readLine()); + + StringTokenizer st = new StringTokenizer(br.readLine()); + parent = new int[N]; + edges = new List[N]; + + for (int i = 0; i < N; i++) { + edges[i] = new ArrayList<>(); + } + + for (int i = 0; i < N; i++) { + parent[i] = Integer.parseInt(st.nextToken()); + if (parent[i] == -1) continue; + edges[parent[i]].add(i); + } + + M = Integer.parseInt(br.readLine()); + } + + private static void DFS(int start) { + if (isLeaf(start)) { + answer++; + return; + } + + for (int next : edges[start]) { + if (next == M) continue; + DFS(next); + } + } + + private static boolean isLeaf(int node) { + if (edges[node].isEmpty()) { + return true; + } + + if (edges[node].size() == 1 && edges[node].get(0) == M) { + return true; + } + + return false; + } +} +```