結果
問題 | No.763 Noelちゃんと木遊び |
ユーザー |
|
提出日時 | 2018-12-11 00:05:51 |
言語 | Java (openjdk 23) |
結果 |
AC
|
実行時間 | 201 ms / 2,000 ms |
コード長 | 4,418 bytes |
コンパイル時間 | 4,400 ms |
コンパイル使用メモリ | 90,968 KB |
実行使用メモリ | 57,724 KB |
最終ジャッジ日時 | 2024-09-24 17:30:47 |
合計ジャッジ時間 | 8,255 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 |
---|---|
other | AC * 21 |
ソースコード
package adv2018;import java.io.ByteArrayInputStream;import java.io.IOException;import java.io.InputStream;import java.io.PrintWriter;import java.util.Arrays;import java.util.InputMismatchException;public class Day11 {InputStream is;PrintWriter out;String INPUT = "";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[][] pars = parents3(g, 0);int[] par = pars[0], ord = pars[1], dep = pars[2];int[] dp = new int[n];int[] ep = new int[n];for(int i = n-1;i >= 0;i--) {int cur = ord[i];dp[cur] = 1;for(int e : g[cur]) {if(par[cur] == e)continue;dp[cur] += Math.max(ep[e], dp[e] - 1);ep[cur] += Math.max(ep[e], dp[e]);}}out.println(Math.max(dp[0], ep[0]));}public static int[][] parents3(int[][] g, int root) {int n = g.length;int[] par = new int[n];Arrays.fill(par, -1);int[] depth = new int[n];depth[0] = 0;int[] q = new int[n];q[0] = root;for (int p = 0, r = 1; p < r; p++) {int cur = q[p];for (int nex : g[cur]) {if (par[cur] != nex) {q[r++] = nex;par[nex] = cur;depth[nex] = depth[cur] + 1;}}}return new int[][] { par, q, depth };}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;}void run() throws Exception{is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());out = new PrintWriter(System.out);long s = System.currentTimeMillis();solve();out.flush();if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");// Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){// @Override// public void run() {// long s = System.currentTimeMillis();// solve();// out.flush();// if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");// }// };// t.start();// t.join();}public static void main(String[] args) throws Exception { new Day11().run(); }private byte[] inbuf = new byte[1024];public int lenbuf = 0, ptrbuf = 0;private int readByte(){if(lenbuf == -1)throw new InputMismatchException();if(ptrbuf >= lenbuf){ptrbuf = 0;try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }if(lenbuf <= 0)return -1;}return inbuf[ptrbuf++];}private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }private double nd() { return Double.parseDouble(ns()); }private char nc() { return (char)skip(); }private String ns(){int b = skip();StringBuilder sb = new StringBuilder();while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')sb.appendCodePoint(b);b = readByte();}return sb.toString();}private char[] ns(int n){char[] buf = new char[n];int b = skip(), p = 0;while(p < n && !(isSpaceChar(b))){buf[p++] = (char)b;b = readByte();}return n == p ? buf : Arrays.copyOf(buf, p);}private int[] na(int n){int[] a = new int[n];for(int i = 0;i < n;i++)a[i] = ni();return a;}private long[] nal(int n){long[] a = new long[n];for(int i = 0;i < n;i++)a[i] = nl();return a;}private char[][] nm(int n, int m) {char[][] map = new char[n][];for(int i = 0;i < n;i++)map[i] = ns(m);return map;}private int[][] nmi(int n, int m) {int[][] map = new int[n][];for(int i = 0;i < n;i++)map[i] = na(m);return map;}private int ni() { return (int)nl(); }private long nl(){long num = 0;int b;boolean minus = false;while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));if(b == '-'){minus = true;b = readByte();}while(true){if(b >= '0' && b <= '9'){num = num * 10 + (b - '0');}else{return minus ? -num : num;}b = readByte();}}private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }}