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‎03do-new30/202503/25 BOJ G4 해킹.md‎

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```java
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import java.util.*;
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import java.io.*;
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public class Main {
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static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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static int n, d, c;
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static List<Info>[] graph; // 인접 리스트
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static class Info implements Comparable<Info> {
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int id;
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int sec;
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public Info(int id, int sec) {
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this.id = id;
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this.sec = sec;
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}
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@Override
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public int compareTo(Info o) {
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return Integer.compare(this.sec, o.sec);
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}
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}
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public static void main(String[] args) throws IOException {
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int T = Integer.parseInt(br.readLine());
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for (int tc = 1; tc <= T; tc++) {
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input();
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// 총 감염되는 컴퓨터 수, 마지막 컴퓨터가 감염되기까지 걸리는 시간
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dijkstra(c);
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}
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br.close();
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}
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private static void dijkstra(int start) {
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PriorityQueue<Info> pq = new PriorityQueue<>();
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int[] dist = new int[n+1];
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for (int i = 0; i < n+1; i++) {
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dist[i] = -1;
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}
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dist[start] = 0;
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pq.add(new Info(start, 0));
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while (!pq.isEmpty()) {
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Info info = pq.poll();
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int current = info.id;
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if (dist[current] < info.sec) continue; // 이미 더 빠르게 방문한 적이 있으면 skip
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for (Info next : graph[current]) {
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if (dist[next.id] == -1 || dist[next.id] > dist[current] + next.sec ) {
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dist[next.id] = dist[current] + next.sec;
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pq.add(next);
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}
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}
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}
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int cnt = 0;
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int time = -1;
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for (int i = 1; i <= n; i++) {
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if (dist[i] == -1) { continue; }
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cnt++;
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time = Integer.max(time, dist[i]);
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}
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// 총 감염되는 컴퓨터 수
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// 감염되기까지 걸리는 시간
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System.out.println(cnt + " " + time);
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}
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private static void input() throws IOException {
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StringTokenizer st = new StringTokenizer(br.readLine());
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n = Integer.parseInt(st.nextToken());
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d = Integer.parseInt(st.nextToken());
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c = Integer.parseInt(st.nextToken());
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graph = new List[n+1];
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for (int i = 1; i < n+1; i++) {
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graph[i] = new ArrayList<>();
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}
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for (int i = 0; i < d; i++) {
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st = new StringTokenizer(br.readLine());
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// 컴퓨터 a가 컴퓨터 b를 의존하며, 컴퓨터 b가 감염되면 s초 후 컴퓨터 a도 감염된다.
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int a = Integer.parseInt(st.nextToken());
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int b = Integer.parseInt(st.nextToken());
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int s = Integer.parseInt(st.nextToken());
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graph[b].add(new Info(a, s));
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}
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}
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}
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```

‎03do-new30/202503/26 BOJ G3 별자리 만들기.md‎

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```java
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import java.io.BufferedReader;
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import java.io.IOException;
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import java.io.InputStreamReader;
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import java.util.*;
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public class Main {
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static class Point {
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double r;
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double c;
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public Point (double r, double c) {
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this.r = r;
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this.c = c;
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}
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}
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static class Edge implements Comparable<Edge>{
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int from;
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int to;
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double weight;
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public Edge(int from, int to, double weight) {
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this.from = from;
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this.to = to;
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this.weight = weight;
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}
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@Override
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public int compareTo(Edge o) {
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return Double.compare(this.weight, o.weight);
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}
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}
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static int n;
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static int[] parents;
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static Point[] points;
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static PriorityQueue<Edge> pq;
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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n = Integer.parseInt(br.readLine());
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points = new Point[n];
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for (int i = 0; i < n; i++) {
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StringTokenizer st = new StringTokenizer(br.readLine());
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double r = Double.parseDouble(st.nextToken());
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double c = Double.parseDouble(st.nextToken());
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points[i] = new Point(r, c);
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}
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// 자기 자신을 포함하는 부분집합 구성
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makeSet();
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// Point간의 거리를 계산해서 PQ에 등록
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pq = new PriorityQueue<>();
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for (int i = 0; i < n-1; i++) {
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for (int j = i+1; j < n; j++) {
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pq.offer(new Edge(i, j, getDist(points[i], points[j])));
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}
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}
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// ans: 별자리를 만드는 최소 비용
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double ans = 0.0;
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int edgeCnt = 0; // Kruskal 알고리즘은 간선이 n-1개 선택되면 종료
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while (!pq.isEmpty() && edgeCnt < n-1) {
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Edge e = pq.poll();
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if (union(e.from, e.to)) { // from, to가 서로소 집합에 속한다면 ans에 비용 추가
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ans += e.weight;
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edgeCnt++;
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}
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}
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System.out.printf("%.2f\n", ans);
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br.close();
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}
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private static void makeSet() {
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parents = new int[n];
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for (int i = 0; i < n; i++) {
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parents[i] = i;
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}
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}
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private static int find(int a) {
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if (a == parents[a]) return a;
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return parents[a] = find(parents[a]);
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}
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private static boolean union(int a, int b) {
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int aRoot = find(a);
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int bRoot = find(b);
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if (aRoot == bRoot) return false;
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if (aRoot < bRoot) {
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parents[bRoot] = aRoot;
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} else {
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parents[aRoot] = bRoot;
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}
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return true;
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}
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private static double getDist(Point x, Point y) {
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return Math.sqrt(Math.pow(x.r - y.r, 2) + Math.pow(x.c - y.c, 2));
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}
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}
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```

‎03do-new30/202503/27 BOJ G2 친구 네트워크.md‎

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```java
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import java.io.*;
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import java.util.*;
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public class Main {
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static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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static int F, cnt;
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static Map<String, Integer> map;
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static int[] parents, friends;
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public static void main(String[] args) throws IOException {
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int T = Integer.parseInt(br.readLine());
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for (int tc = 1; tc <= T; tc++) {
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F = Integer.parseInt(br.readLine());
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map = new HashMap<>();
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cnt = 0;
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makeSet();
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init();
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for (int i = 0 ; i < F; i++) {
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StringTokenizer st = new StringTokenizer(br.readLine());
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String name1 = st.nextToken();
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String name2 = st.nextToken();
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addName(name1); // 이름 관리
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addName(name2);
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union(map.get(name1), map.get(name2));
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// 두 사람의 친구 네트워크에 몇 명이 있는지 구한다.
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int root = find(map.get(name1));
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System.out.println(friends[root]);
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}
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}
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br.close();
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}
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static void addName(String name) {
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if (map.containsKey(name)) return;
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map.put(name, cnt++);
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}
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static void init() {
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// friends[i] = i가 집합의 대표자일 때, 해당 집합에 속하는 친구들의 수
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friends = new int[F*2];
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for (int i = 0; i < F*2; i++) {
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friends[i] = 1; // 초기에는 자기 자신만 친구...
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}
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}
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static void makeSet() {
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parents = new int[F * 2]; // F개 관계 -> 최대 F*2명의 사람 존재 가능
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for (int i = 0; i < F * 2; i++) {
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parents[i] = i;
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}
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}
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static int find(int a) {
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if (a == parents[a]) return a;
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return parents[a] = find(parents[a]);
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}
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static boolean union(int a, int b) {
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int aRoot = find(a);
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int bRoot = find(b);
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if (aRoot == bRoot) return false;
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if (aRoot < bRoot) {
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parents[bRoot] = aRoot;
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friends[aRoot] += friends[bRoot]; // 친구 수 합치깅
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} else {
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parents[aRoot] = bRoot;
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friends[bRoot] += friends[aRoot]; // 친구 수 합치깅
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}
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return true;
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}
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}
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```

‎03do-new30/202504/01 BOJ G3 우주신과의 교감.md‎

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```java
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import java.util.*;
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import java.io.*;
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import java.awt.Point;
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public class Main {
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static int N, M;
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static Point[] points;
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static int[] parents;
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static PriorityQueue<Edge> pq;
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static class Edge implements Comparable<Edge>{
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int from, to;
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double wt;
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public Edge(int from, int to, double wt) {
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this.from = from;
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this.to = to;
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this.wt = wt;
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}
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@Override
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public int compareTo(Edge o) {
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return Double.compare(this.wt, o.wt);
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}
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}
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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StringTokenizer st = new StringTokenizer(br.readLine());
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N = Integer.parseInt(st.nextToken()); // 정점의 개수
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M = Integer.parseInt(st.nextToken()); // 이미 연결된 통로의 개수
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points = new Point[N+1];
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for (int i = 1; i < N+1; i++) {
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st = new StringTokenizer(br.readLine());
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int x = Integer.parseInt(st.nextToken());
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int y = Integer.parseInt(st.nextToken());
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points[i] = new Point(x, y);
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}
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makeSet();
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for (int i = 0; i < M; i++) {
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// 이미 연결된 정점들에 대해 union
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st = new StringTokenizer(br.readLine());
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int a = Integer.parseInt(st.nextToken());
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int b = Integer.parseInt(st.nextToken());
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union(a, b);
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}
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makePQ();
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double result = kruskal();
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System.out.printf("%.2f\n", result);
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br.close();
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}
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static double kruskal() {
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double result = 0.0;
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while (!pq.isEmpty()) {
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Edge e = pq.poll();
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if (union(e.to, e.from)) {
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result += e.wt;
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}
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}
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return result;
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}
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static void makePQ() {
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pq = new PriorityQueue<>();
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for (int i = 1; i < N; i++) {
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for (int j = i+1; j < N+1; j++) {
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pq.add(new Edge(i, j, getDist(points[i], points[j])));
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}
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}
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}
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static void makeSet() {
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parents = new int[N+1];
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for (int i = 1; i < N+1; i++) {
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parents[i] = i;
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}
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}
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static int find(int a) {
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if (parents[a] == a) return a;
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return parents[a] = find(parents[a]);
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}
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static boolean union(int a, int b) {
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int aRoot = find(a);
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int bRoot = find(b);
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if (aRoot == bRoot) return false;
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if (aRoot < bRoot) {
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parents[bRoot] = aRoot;
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} else {
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parents[bRoot] = aRoot;
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}
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return true;
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}
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static double getDist(Point a, Point b) {
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return Math.sqrt(Math.pow(a.x - b.x, 2) + Math.pow(a.y - b.y, 2));
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}
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}
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```

‎README.md‎

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</tr>
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<tr>
33-
<td align="center"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/khj20006/khj20006/202503">3월 제출</td>
34-
<td align="center"style="border-right : 0.5px solid gray"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/suyeun84/suyeun84/202503" >3월 제출</td>
35-
<td align="center"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/03do-new30/03do-new30/202503">3월 제출</td>
36-
<td align="center"style="border-right : 0.5px solid gray"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/ShinHeeEul/ShinHeeEul/202503">3월 제출</td>
37-
<td align="center"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/Seol-JY/Seol-JY/202503">3월 제출</td>
38-
<td align="center"style="border-right : 0.5px solid gray"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/lkhyun/lkhyun/202503">3월 제출</td>
33+
<td align="center"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/khj20006/khj20006/202505">5월 제출</td>
34+
<td align="center"style="border-right : 0.5px solid gray"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/suyeun84/suyeun84/202505" >5월 제출</td>
35+
<td align="center"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/03do-new30/03do-new30/202505">5월 제출</td>
36+
<td align="center"style="border-right : 0.5px solid gray"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/ShinHeeEul/ShinHeeEul/202505">5월 제출</td>
37+
<td align="center"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/Seol-JY/Seol-JY/202505">5월 제출</td>
38+
<td align="center"style="border-right : 0.5px solid gray"><a href="https://github.com/AlgorithmWithGod/Algorithm/new/lkhyun/lkhyun/202505">5월 제출</td>
3939
</tr>
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<!-- <tr>
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<td align = "center" colspan = "5" style="border-right : 0.5px solid gray">Full-Stack</td>

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