結果
問題 | No.763 Noelちゃんと木遊び |
ユーザー |
|
提出日時 | 2018-12-23 10:43:54 |
言語 | Java (openjdk 23) |
結果 |
AC
|
実行時間 | 345 ms / 2,000 ms |
コード長 | 2,935 bytes |
コンパイル時間 | 3,045 ms |
コンパイル使用メモリ | 80,064 KB |
実行使用メモリ | 58,180 KB |
最終ジャッジ日時 | 2024-09-25 10:30:23 |
合計ジャッジ時間 | 9,473 ms |
ジャッジサーバーID (参考情報) |
judge3 / judge4 |
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ファイルパターン | 結果 |
---|---|
other | AC * 21 |
ソースコード
import java.io.IOException;import java.io.InputStream;import java.util.ArrayDeque;import java.util.ArrayList;import java.util.Arrays;import java.util.NoSuchElementException;class Main {public static void main(String[] args) {new Main().run();}void run() {Scanner sc = new Scanner();int N = sc.nextInt();boolean[] ex = new boolean[N];int[] deg = new int[N];Arrays.fill(ex, true);ArrayDeque<Integer> pd = new ArrayDeque<Integer>();ArrayList<Integer>[] g = new ArrayList[N];for (int i = 0; i < N; ++i) {g[i] = new ArrayList<>();}for (int i = 0; i < N - 1; ++i) {int u = sc.nextInt() - 1;int v = sc.nextInt() - 1;g[u].add(v);g[v].add(u);++deg[u];++deg[v];}if (N == 1) {System.out.println(1);return;}for (int i = 0; i < N; ++i) {if (deg[i] == 1)pd.add(i);}int ans = 0;while (!pd.isEmpty()) {int u = pd.poll();if (!ex[u])continue;for (int v : g[u]) {if (!ex[v])continue;ex[v] = false;for (int v2 : g[v]) {if (!ex[v2])continue;--deg[v2];if (deg[v2] == 0) {++ans;ex[v2] = false;} else if (deg[v2] == 1) {pd.add(v2);}}}}System.out.println(ans);}void tr(Object... o) {System.out.println(Arrays.deepToString(o));}}class Scanner {private final InputStream in = System.in;private final byte[] buffer = new byte[1024];private int ptr = 0;private int buflen = 0;private boolean hasNextByte() {if (ptr < buflen) {return true;} else {ptr = 0;try {buflen = in.read(buffer);} catch (IOException e) {e.printStackTrace();}if (buflen <= 0) {return false;}}return true;}private int readByte() {if (hasNextByte())return buffer[ptr++];elsereturn -1;}private static boolean isPrintableChar(int c) {return 33 <= c && c <= 126;}private void skipUnprintable() {while (hasNextByte() && !isPrintableChar(buffer[ptr]))ptr++;}public boolean hasNext() {skipUnprintable();return hasNextByte();}public String next() {if (!hasNext())throw new NoSuchElementException();StringBuilder sb = new StringBuilder();int b = readByte();while (isPrintableChar(b)) {sb.appendCodePoint(b);b = readByte();}return sb.toString();}public long nextLong() {if (!hasNext())throw new NoSuchElementException();long n = 0;boolean minus = false;int b = readByte();if (b == '-') {minus = true;b = readByte();}if (b < '0' || '9' < b) {throw new NumberFormatException();}while (true) {if ('0' <= b && b <= '9') {n *= 10;n += b - '0';} else if (b == -1 || !isPrintableChar(b)) {return minus ? -n : n;} else {throw new NumberFormatException();}b = readByte();}}public int nextInt() {return (int) nextLong();}}