From 6084a34a25ed4f1e3c50daff6bc2336bf48ac9a7 Mon Sep 17 00:00:00 2001 From: zinnnn37 Date: Sun, 31 Aug 2025 18:52:35 +0900 Subject: [PATCH] =?UTF-8?q?[20250831]=20BOJ=20/=20G5=20/=20=ED=8A=B8?= =?UTF-8?q?=EB=A6=AC=EC=99=80=20=EC=BF=BC=EB=A6=AC=20/=20=EA=B9=80?= =?UTF-8?q?=EB=AF=BC=EC=A7=84?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...4\354\231\200 \354\277\274\353\246\254.md" | 84 +++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 "zinnnn37/202508/31 BOJ G5 \355\212\270\353\246\254\354\231\200 \354\277\274\353\246\254.md" diff --git "a/zinnnn37/202508/31 BOJ G5 \355\212\270\353\246\254\354\231\200 \354\277\274\353\246\254.md" "b/zinnnn37/202508/31 BOJ G5 \355\212\270\353\246\254\354\231\200 \354\277\274\353\246\254.md" new file mode 100644 index 00000000..a97338c1 --- /dev/null +++ "b/zinnnn37/202508/31 BOJ G5 \355\212\270\353\246\254\354\231\200 \354\277\274\353\246\254.md" @@ -0,0 +1,84 @@ +```java +import java.io.*; +import java.util.ArrayList; +import java.util.List; +import java.util.StringTokenizer; + +public class BJ_15681_트리와_쿼리 { + + private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); + private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); + private static final StringBuilder sb = new StringBuilder(); + private static StringTokenizer st; + + private static int N; + private static int R; + private static int Q; + + private static int[] dp; + private static boolean[] visited; + private static List[] tree; + + public static void main(String[] args) throws IOException { + init(); + sol(); + } + + private static void init() throws IOException { + st = new StringTokenizer(br.readLine()); + + N = Integer.parseInt(st.nextToken()); + R = Integer.parseInt(st.nextToken()); + Q = Integer.parseInt(st.nextToken()); + + tree = new List[N + 1]; + for (int i = 1; i <= N; i++) { + tree[i] = new ArrayList<>(); + } + + for (int i = 0; i < N - 1; i++) { + st = new StringTokenizer(br.readLine()); + int u = Integer.parseInt(st.nextToken()); + int v = Integer.parseInt(st.nextToken()); + + tree[u].add(v); + tree[v].add(u); + } + visited = new boolean[N + 1]; + dp = new int[N + 1]; + } + + private static void sol() throws IOException { + dp[R] = makeDP(R); + + for (int i = 0; i < Q; i++) { + int q = Integer.parseInt(br.readLine()); + + sb.append(dp[q]).append("\n"); + } + bw.write(sb.toString()); + bw.flush(); + bw.close(); + br.close(); + } + + private static int makeDP(int parent) { + if (dp[parent] != 0) return dp[parent]; + + int cnt = 1; + for (int i = 0; i < tree[parent].size(); i++) { + int child = tree[parent].get(i); + + if (visited[child] || child == R) { + continue; + } + + visited[child] = true; + dp[child] = makeDP(child); + cnt += dp[child]; + } + return cnt; + } + +} +``` \ No newline at end of file