結果
問題 | No.2205 Lights Out on Christmas Tree |
ユーザー |
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提出日時 | 2023-02-13 18:29:47 |
言語 | Java (openjdk 23) |
結果 |
AC
|
実行時間 | 806 ms / 2,000 ms |
コード長 | 2,479 bytes |
コンパイル時間 | 2,796 ms |
コンパイル使用メモリ | 84,692 KB |
実行使用メモリ | 117,756 KB |
最終ジャッジ日時 | 2024-07-16 11:50:43 |
合計ジャッジ時間 | 25,909 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 37 |
ソースコード
import java.io.*;import java.util.*;import java.util.stream.*;public class Main {static ArrayList<ArrayList<Integer>> graph = new ArrayList<>();static boolean[] isBlack;public static void main(String[] args) throws Exception {Scanner sc = new Scanner();int n = sc.nextInt();for (int i = 0; i < n; i++) {graph.add(new ArrayList<>());}for (int i = 0; i < n - 1; i++) {int a = sc.nextInt() - 1;int b = sc.nextInt() - 1;graph.get(a).add(b);graph.get(b).add(a);}isBlack = new boolean[n];for (int i = 0; i < n; i++) {isBlack[i] = (sc.nextInt() == 1);}int ans = getCount(0, 0);if (isBlack[0]) {System.out.println(ans);} else {System.out.println(-1);}}static int getCount(int idx, int p) {int count = 0;for (int x : graph.get(idx)) {if (x == p) {continue;}count += getCount(x, idx);if (!isBlack[x]) {count++;isBlack[idx] ^= true;}}return count;}}class Utilities {static String arrayToLineString(Object[] arr) {return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));}static String arrayToLineString(int[] arr) {return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));}}class Scanner {BufferedReader br = new BufferedReader(new InputStreamReader(System.in));StringTokenizer st = new StringTokenizer("");StringBuilder sb = new StringBuilder();public Scanner() throws Exception {}public int nextInt() throws Exception {return Integer.parseInt(next());}public long nextLong() throws Exception {return Long.parseLong(next());}public double nextDouble() throws Exception {return Double.parseDouble(next());}public int[] nextIntArray() throws Exception {return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();}public String next() throws Exception {while (!st.hasMoreTokens()) {st = new StringTokenizer(br.readLine());}return st.nextToken();}}