diff --git "a/03do-new30/202503/13 BOJ G3 \354\244\204 \354\204\270\354\232\260\352\270\260.md" "b/03do-new30/202503/13 BOJ G3 \354\244\204 \354\204\270\354\232\260\352\270\260.md" new file mode 100644 index 00000000..fba2c745 --- /dev/null +++ "b/03do-new30/202503/13 BOJ G3 \354\244\204 \354\204\270\354\232\260\352\270\260.md" @@ -0,0 +1,67 @@ +```java +import java.util.*; +import java.io.*; + +public class Main { + static int N, M; + static List[] graph; + static int[] indegree; + public static void main(String[] args) throws IOException { + input(); + getIndegree(); + List order = topologySort(); + for (int num : order) { + System.out.print(num + " "); + } + System.out.println(); + } + + static ArrayList topologySort() { + ArrayList orderList = new ArrayList<>(); // 정점의 방문 순서 + Queue q = new ArrayDeque<>(); + for (int i = 1; i < N+1; i++) { + if (indegree[i] == 0) { + q.offer(i); + } + } + + while (!q.isEmpty()) { + int node = q.poll(); + orderList.add(node); + for (int next : graph[node]) { + if (--indegree[next] == 0) q.offer(next); + } + } + return orderList; + } + + static void getIndegree() { + indegree = new int[N+1]; + for (int from = 1; from < N+1; from++) { + for (int to : graph[from] ){ + // 진입 차수 기록 + indegree[to]++; + } + } + } + + static void input() throws IOException { + BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); + StringTokenizer st = new StringTokenizer(br.readLine()); + N = Integer.parseInt(st.nextToken()); + M = Integer.parseInt(st.nextToken()); + graph = new List[N+1]; + for (int i = 1; i < N+1; i++) { + graph[i] = new ArrayList<>(); + } + for (int i = 0; i < M; i++) { + st = new StringTokenizer(br.readLine()); + int a = Integer.parseInt(st.nextToken()); + int b = Integer.parseInt(st.nextToken()); + graph[a].add(b); + } + br.close(); + + } +} +```