diff --git "a/JHLEE325/202508/20 BOJ G4 \352\260\200\354\232\264\353\215\260\354\204\234 \353\247\214\353\202\230\352\270\260.md" "b/JHLEE325/202508/20 BOJ G4 \352\260\200\354\232\264\353\215\260\354\204\234 \353\247\214\353\202\230\352\270\260.md" new file mode 100644 index 00000000..b1385b52 --- /dev/null +++ "b/JHLEE325/202508/20 BOJ G4 \352\260\200\354\232\264\353\215\260\354\204\234 \353\247\214\353\202\230\352\270\260.md" @@ -0,0 +1,82 @@ +```java +import java.io.*; +import java.util.*; + +public class Main { + + static int n, m, k; + static int[][] map; + static final int INF = 987654321; + + public static void main(String[] args) throws Exception { + BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); + StringTokenizer st = new StringTokenizer(br.readLine()); + + n = Integer.parseInt(st.nextToken()); + m = Integer.parseInt(st.nextToken()); + + map = new int[n][n]; + for (int i = 0; i < n; i++) { + Arrays.fill(map[i], INF); + map[i][i] = 0; + } + + for (int i = 0; i < m; i++) { + st = new StringTokenizer(br.readLine()); + int from = Integer.parseInt(st.nextToken()) - 1; + int to = Integer.parseInt(st.nextToken()) - 1; + int cost = Integer.parseInt(st.nextToken()); + if (cost < map[from][to]) map[from][to] = cost; + } + + for (int k = 0; k < n; k++) { + for (int i = 0; i < n; i++) { + if (map[i][k] == INF) continue; + for (int j = 0; j < n; j++) { + if (map[k][j] == INF) continue; + map[i][j] = Math.min(map[i][j], map[i][k] + map[k][j]); + } + } + } + + k = Integer.parseInt(br.readLine()); + int[] friend = new int[k]; + st = new StringTokenizer(br.readLine()); + for (int i = 0; i < k; i++) { + friend[i] = Integer.parseInt(st.nextToken()) - 1; + } + + int best = INF; + ArrayList ans = new ArrayList<>(); + + for (int v = 0; v < n; v++) { + int worst = 0; + boolean ok = true; + for (int s : friend) { + if (map[s][v] == INF || map[v][s] == INF) { + ok = false; + break; + } + worst = Math.max(worst, map[s][v] + map[v][s]); + } + if (!ok) continue; + + if (worst < best) { + best = worst; + ans.clear(); + ans.add(v + 1); + } else if (worst == best) { + ans.add(v + 1); + } + } + + StringBuilder sb = new StringBuilder(); + for (int i = 0; i < ans.size(); i++) { + if (i > 0) sb.append(' '); + sb.append(ans.get(i)); + } + System.out.println(sb.toString()); + } +} + +```