結果

問題 No.763 Noelちゃんと木遊び
ユーザー hiromi_ayase
提出日時 2018-12-13 01:45:12
言語 Java
(openjdk 23)
結果
AC  
実行時間 312 ms / 2,000 ms
コード長 3,376 bytes
コンパイル時間 2,934 ms
コンパイル使用メモリ 89,872 KB
実行使用メモリ 75,140 KB
最終ジャッジ日時 2024-09-25 04:03:38
合計ジャッジ時間 9,907 ms
ジャッジサーバーID
(参考情報)
judge4 / judge5
このコードへのチャレンジ
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ファイルパターン 結果
other AC * 21
権限があれば一括ダウンロードができます

ソースコード

diff #
プレゼンテーションモードにする

public class Main {
private static void solve() {
int n = ni();
int[] from = new int[n - 1];
int[] to = new int[n - 1];
for (int i = 0; i < n - 1; i++) {
from[i] = ni() - 1;
to[i] = ni() - 1;
}
int[][] g = packU(n, from, to);
int[] ret = dfs(0, -1, g);
System.out.println(Math.max(ret[0], ret[1]));
}
private static int[] dfs(int now, int pre, int[][] g) {
int[] ret = {0, 1};
for (int next : g[now]) {
if (next == pre)
continue;
int[] v = dfs(next, now, g);
ret[0] += Math.max(v[0], v[1]);
ret[1] += Math.max(v[0], v[1] - 1);
}
return ret;
}
static int[][] packU(int n, int[] from, int[] to) {
int[][] g = new int[n][];
int[] p = new int[n];
for (int f : from)
p[f]++;
for (int t : to)
p[t]++;
for (int i = 0; i < n; i++)
g[i] = new int[p[i]];
for (int i = 0; i < from.length; i++) {
g[from[i]][--p[from[i]]] = to[i];
g[to[i]][--p[to[i]]] = from[i];
}
return g;
}
public static void main(String[] args) {
new Thread(null, new Runnable() {
@Override
public void run() {
long start = System.currentTimeMillis();
String debug = args.length > 0 ? args[0] : null;
if (debug != null) {
try {
is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug));
} catch (Exception e) {
throw new RuntimeException(e);
}
}
reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768);
solve();
out.flush();
tr((System.currentTimeMillis() - start) + "ms");
}
}, "", 64000000).start();
}
private static java.io.InputStream is = System.in;
private static java.io.PrintWriter out = new java.io.PrintWriter(System.out);
private static java.util.StringTokenizer tokenizer = null;
private static java.io.BufferedReader reader;
public static String next() {
while (tokenizer == null || !tokenizer.hasMoreTokens()) {
try {
tokenizer = new java.util.StringTokenizer(reader.readLine());
} catch (Exception e) {
throw new RuntimeException(e);
}
}
return tokenizer.nextToken();
}
private static double nd() {
return Double.parseDouble(next());
}
private static long nl() {
return Long.parseLong(next());
}
private static int[] na(int n) {
int[] a = new int[n];
for (int i = 0; i < n; i++)
a[i] = ni();
return a;
}
private static char[] ns() {
return next().toCharArray();
}
private static long[] nal(int n) {
long[] a = new long[n];
for (int i = 0; i < n; i++)
a[i] = nl();
return a;
}
private static int[][] ntable(int n, int m) {
int[][] table = new int[n][m];
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
table[i][j] = ni();
}
}
return table;
}
private static int[][] nlist(int n, int m) {
int[][] table = new int[m][n];
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
table[j][i] = ni();
}
}
return table;
}
private static int ni() {
return Integer.parseInt(next());
}
private static void tr(Object... o) {
if (is != System.in)
System.out.println(java.util.Arrays.deepToString(o));
}
}
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