diff --git "a/JHLEE325/202507/20 BOJ G4 \354\227\254\355\226\211\352\260\200\354\236\220.md" "b/JHLEE325/202507/20 BOJ G4 \354\227\254\355\226\211\352\260\200\354\236\220.md" new file mode 100644 index 00000000..ae4c01c0 --- /dev/null +++ "b/JHLEE325/202507/20 BOJ G4 \354\227\254\355\226\211\352\260\200\354\236\220.md" @@ -0,0 +1,56 @@ +```java +import java.io.BufferedReader; +import java.io.InputStreamReader; +import java.util.*; + +public class Main { + + public static void main(String[] args) throws Exception { + BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); + StringTokenizer st; + + int n = Integer.parseInt(br.readLine()); + int m = Integer.parseInt(br.readLine()); + + int[][] map = new int[n][n]; + + for (int i = 0; i < n; i++) { + st = new StringTokenizer(br.readLine()); + for (int j = 0; j < n; j++) { + map[i][j] = Integer.parseInt(st.nextToken()); + if (i == j) { + map[i][j] = 1; + } + } + } + + for (int k = 0; k < n; k++) { + for (int i = 0; i < n; i++) { + for (int j = 0; j < n; j++) { + if (map[i][k] == 1 && map[k][j] == 1) + map[i][j] = 1; + } + } + } + + int[] route = new int[m]; + st = new StringTokenizer(br.readLine()); + for (int i = 0; i < m; i++) { + route[i] = Integer.parseInt(st.nextToken()); + } + + if (m == 1) { + System.out.println("YES"); + return; + } + + for (int i = 0; i < m - 1; i++) { + if (map[route[i] - 1][route[i + 1] - 1] == 0) { + System.out.println("NO"); + return; + } + } + System.out.println("YES"); + } +} +```