結果

問題 No.196 典型DP (1)
ユーザー ぴろずぴろず
提出日時 2015-04-27 00:26:25
言語 Java21
(openjdk 21)
結果
AC  
実行時間 298 ms / 2,000 ms
コード長 5,005 bytes
コンパイル時間 2,439 ms
コンパイル使用メモリ 80,140 KB
実行使用メモリ 87,224 KB
最終ジャッジ日時 2024-07-05 03:19:00
合計ジャッジ時間 10,804 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge1
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 57 ms
49,752 KB
testcase_01 AC 55 ms
36,564 KB
testcase_02 AC 55 ms
36,796 KB
testcase_03 AC 57 ms
36,436 KB
testcase_04 AC 56 ms
36,888 KB
testcase_05 AC 57 ms
36,720 KB
testcase_06 AC 57 ms
36,768 KB
testcase_07 AC 55 ms
36,872 KB
testcase_08 AC 56 ms
36,644 KB
testcase_09 AC 56 ms
36,756 KB
testcase_10 AC 56 ms
37,052 KB
testcase_11 AC 57 ms
36,568 KB
testcase_12 AC 56 ms
36,452 KB
testcase_13 AC 57 ms
36,792 KB
testcase_14 AC 58 ms
36,820 KB
testcase_15 AC 61 ms
37,912 KB
testcase_16 AC 104 ms
46,604 KB
testcase_17 AC 153 ms
52,376 KB
testcase_18 AC 196 ms
58,708 KB
testcase_19 AC 245 ms
68,700 KB
testcase_20 AC 207 ms
84,724 KB
testcase_21 AC 198 ms
87,200 KB
testcase_22 AC 244 ms
87,004 KB
testcase_23 AC 257 ms
87,072 KB
testcase_24 AC 250 ms
86,752 KB
testcase_25 AC 222 ms
87,044 KB
testcase_26 AC 229 ms
86,880 KB
testcase_27 AC 227 ms
86,944 KB
testcase_28 AC 241 ms
86,692 KB
testcase_29 AC 248 ms
86,632 KB
testcase_30 AC 270 ms
86,688 KB
testcase_31 AC 262 ms
86,424 KB
testcase_32 AC 263 ms
86,248 KB
testcase_33 AC 258 ms
86,520 KB
testcase_34 AC 235 ms
86,980 KB
testcase_35 AC 263 ms
86,628 KB
testcase_36 AC 298 ms
86,852 KB
testcase_37 AC 249 ms
87,224 KB
testcase_38 AC 253 ms
86,696 KB
testcase_39 AC 261 ms
86,460 KB
testcase_40 AC 242 ms
84,800 KB
testcase_41 AC 55 ms
49,812 KB
testcase_42 AC 56 ms
36,536 KB
testcase_43 AC 55 ms
36,920 KB
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ソースコード

diff # 

package no195;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.InputMismatchException;
import java.util.NoSuchElementException;

public class Main {
	public static long MOD = 1000000007;
	public static void main(String[] args) {
		new Main().solve();
	}

	IO io = new IO();
	int n;
	int k;
	ArrayList<Integer>[] tree;
	ArrayList<Integer>[] child;
	long[][] dp;

	@SuppressWarnings("unchecked")
	void solve() {
		n = io.nextInt();
		k = io.nextInt();
		tree = new ArrayList[n];
		child = new ArrayList[n];
		for(int i=0;i<n;i++) {
			tree[i] = new ArrayList<>();
			child[i] = new ArrayList<>();
		}
		for(int i=0;i<n-1;i++) {
			int a = io.nextInt();
			int b = io.nextInt();
			tree[a].add(b);
			tree[b].add(a);
		}
		dfs(-1,0);
		dp = new long[n][n+1];
		dfs2(0);

		System.out.println(dp[0][k]);
//		System.out.println(Arrays.deepToString(dp));
	}

	void dfs(int parent,int v) {
		for(int c:tree[v]) {
			if (c != parent) {
				child[v].add(c);
				dfs(v,c);
			}
		}
	}

	int dfs2(int v) {
		int vnum = 1;
		dp[v][0] = 1;
		for(int c:child[v]) {
			int right = dfs2(c);
			vnum += right;
			for(int i=vnum;i>=0;i--) {
				if (dp[v][i] == 0) {
					continue;
				}
				for(int j=Math.min(vnum-i, right);j>=1;j--) {
					dp[v][i+j] = (dp[v][i+j] + dp[v][i] * dp[c][j]) % MOD;
				}
				dp[v][i] = (dp[v][i] * dp[c][0]) % MOD;
//				System.out.println(v + ":" + Arrays.toString(dp[v]));
			}
		}
		dp[v][vnum] += 1;
		return vnum;
	}



}
class IO extends PrintWriter {
	private final InputStream in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;

	public IO() { this(System.in);}
	public IO(InputStream source) { super(System.out); this.in = source;}
	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++]; else return -1;}
	private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
	private static boolean isNewLine(int c) { return c == '\n' || c == '\r';}
	public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
	public boolean hasNextLine() { while(hasNextByte() && isNewLine(buffer[ptr])) ptr++; 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 char[] nextCharArray(int len) {
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		char[] s = new char[len];
		int i = 0;
		int b = readByte();
		while(isPrintableChar(b)) {
			if (i == len) {
				throw new InputMismatchException();
			}
			s[i++] = (char) b;
			b = readByte();
		}
		return s;
	}
	public String nextLine() {
		if (!hasNextLine()) {
			throw new NoSuchElementException();
		}
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while(!isNewLine(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() {
		long nl = nextLong();
		if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) {
			throw new NumberFormatException();
		}
		return (int) nl;
	}
	public char nextChar() {
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		return (char) readByte();
	}
	public double nextDouble() { return Double.parseDouble(next());}
	public int[] nextIntArray(int n) { int[] a = new int[n]; for(int i=0;i<n;i++) a[i] = nextInt(); return a;}
	public long[] nextLongArray(int n) { long[] a = new long[n]; for(int i=0;i<n;i++) a[i] = nextLong(); return a;}
	public double[] nextDoubleArray(int n) { double[] a = new double[n]; for(int i=0;i<n;i++) a[i] = nextDouble(); return a;}
	public void nextIntArrays(int[]... a) { for(int i=0;i<a[0].length;i++) for(int j=0;j<a.length;j++) a[j][i] = nextInt();}
	public int[][] nextIntMatrix(int n,int m) { int[][] a = new int[n][]; for(int i=0;i<n;i++) a[i] = nextIntArray(m); return a;}
	public char[][] nextCharMap(int n,int m) { char[][] a = new char[n][]; for(int i=0;i<n;i++) a[i] = nextCharArray(m); return a;}
	public void close() { super.close(); try {in.close();} catch (IOException e) {}}
}
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