From d374b9dc41e693a19f30593f752913bf7306147d Mon Sep 17 00:00:00 2001 From: Ukj0ng <90972240+Ukj0ng@users.noreply.github.com> Date: Fri, 3 Oct 2025 22:30:25 +0900 Subject: [PATCH] =?UTF-8?q?[20251002]=20BOJ=20/=20G3=20/=20=EA=B0=9C?= =?UTF-8?q?=EA=B5=AC=EB=A6=AC=20=EC=A0=90=ED=94=84=20/=20=ED=95=9C?= =?UTF-8?q?=EC=A2=85=EC=9A=B1?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...4\353\246\254 \354\240\220\355\224\204.md" | 105 ++++++++++++++++++ 1 file changed, 105 insertions(+) create mode 100644 "Ukj0ng/202510/02 BOJ G3 \352\260\234\352\265\254\353\246\254 \354\240\220\355\224\204.md" diff --git "a/Ukj0ng/202510/02 BOJ G3 \352\260\234\352\265\254\353\246\254 \354\240\220\355\224\204.md" "b/Ukj0ng/202510/02 BOJ G3 \352\260\234\352\265\254\353\246\254 \354\240\220\355\224\204.md" new file mode 100644 index 00000000..a638fbe0 --- /dev/null +++ "b/Ukj0ng/202510/02 BOJ G3 \352\260\234\352\265\254\353\246\254 \354\240\220\355\224\204.md" @@ -0,0 +1,105 @@ +``` +import java.io.*; +import java.util.Arrays; +import java.util.StringTokenizer; + +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 int[][] trees, queries; + private static int[] uf, size; + private static int N, Q; + + public static void main(String[] args) throws IOException { + init(); + unionFind(); + + for (int[] query : queries) { + if (uf[query[0]] == uf[query[1]]) bw.write("1" + "\n"); + else bw.write("0" + "\n"); + } + bw.flush(); + bw.close(); + br.close(); + } + + private static void init() throws IOException { + StringTokenizer st = new StringTokenizer(br.readLine()); + N = Integer.parseInt(st.nextToken()); + Q = Integer.parseInt(st.nextToken()); + + trees = new int[N+1][3]; + queries = new int[Q][2]; + uf = new int[N+1]; + size = new int[N+1]; + + + for (int i = 1; i <= N; i++) { + st = new StringTokenizer(br.readLine()); + int x1 = Integer.parseInt(st.nextToken()); + int x2 = Integer.parseInt(st.nextToken()); + int y = Integer.parseInt(st.nextToken()); + + trees[i][0] = x1; + trees[i][1] = x2; + trees[i][2] = i; + + uf[i] = i; + size[i] = 1; + } + + for (int i = 0; i < Q; i++) { + st = new StringTokenizer(br.readLine()); + int start = Integer.parseInt(st.nextToken()); + int end = Integer.parseInt(st.nextToken()); + + queries[i][0] = start; + queries[i][1] = end; + } + + Arrays.sort(trees, (o1, o2) -> { + if (o1[0] == o2[0]) return Integer.compare(o1[1], o2[1]); + return Integer.compare(o1[0], o2[0]); + }); + } + + private static void unionFind() { + int maxEnd = trees[1][1]; + int start = 1; + + for (int i = 2; i <= N; i++) { + if (valid(maxEnd, trees[i][0])) { + union(trees[start][2], trees[i][2]); + } else { + start = i; + } + maxEnd = Math.max(maxEnd, trees[i][1]); + } + } + + private static boolean valid(int x2, int x3) { + return x2 >= x3; + } + + private static void union(int x, int y) { + int X = find(x); + int Y = find(y); + + if (X == Y) return; + + if (size[X] < size[Y]) { + uf[X] = Y; + size[Y] += size[X]; + } else { + uf[Y] = X; + size[X] += size[Y]; + } + } + + private static int find(int x) { + if (uf[x] == x) return x; + + return uf[x] = find(uf[x]); + } +} +```