結果

問題 No.806 木を道に
ユーザー OlandOland
提出日時 2019-03-22 23:16:38
言語 Java21
(openjdk 21)
結果
AC  
実行時間 409 ms / 2,000 ms
コード長 4,219 bytes
コンパイル時間 2,856 ms
コンパイル使用メモリ 79,356 KB
実行使用メモリ 77,820 KB
最終ジャッジ日時 2023-10-19 10:42:56
合計ジャッジ時間 10,175 ms
ジャッジサーバーID
（参考情報） 		judge13 / judge15
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 56 ms
53,284 KB
testcase_01 AC 56 ms
53,292 KB
testcase_02 AC 56 ms
53,300 KB
testcase_03 AC 56 ms
52,144 KB
testcase_04 AC 55 ms
52,184 KB
testcase_05 AC 57 ms
53,292 KB
testcase_06 AC 56 ms
53,296 KB
testcase_07 AC 55 ms
53,288 KB
testcase_08 AC 56 ms
52,184 KB
testcase_09 AC 57 ms
52,148 KB
testcase_10 AC 161 ms
60,976 KB
testcase_11 AC 153 ms
61,080 KB
testcase_12 AC 389 ms
73,024 KB
testcase_13 AC 258 ms
65,204 KB
testcase_14 AC 380 ms
72,884 KB
testcase_15 AC 398 ms
73,128 KB
testcase_16 AC 202 ms
60,400 KB
testcase_17 AC 370 ms
68,888 KB
testcase_18 AC 121 ms
57,880 KB
testcase_19 AC 166 ms
61,168 KB
testcase_20 AC 345 ms
68,768 KB
testcase_21 AC 233 ms
63,100 KB
testcase_22 AC 394 ms
74,840 KB
testcase_23 AC 409 ms
74,824 KB
testcase_24 AC 187 ms
65,248 KB
testcase_25 AC 261 ms
72,804 KB
testcase_26 AC 154 ms
61,104 KB
testcase_27 AC 290 ms
77,820 KB
testcase_28 AC 78 ms
53,872 KB
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ソースコード

diff # 

import java.io.*;
import java.util.*;
import java.util.Map.Entry;

public class Main {
	
	final boolean isDebug = false;
	String fileName = "input.txt";
	FastScanner sc;
	//PrintWriter out;
	final int MOD = (int)1e9+7;
	final int INF = Integer.MAX_VALUE / 2;
		
	/* solve */
	
	void solve() throws Exception{
		int N = sc.nextInt();
		ArrayList<ArrayList<Integer>> G = new ArrayList<ArrayList<Integer>>();
		for(int i = 0; i < N; i++) G.add(new ArrayList<Integer>());
		for(int i = 0; i < N-1; i++){
			int a = sc.nextInt()-1, b = sc.nextInt()-1;
			G.get(a).add(b); G.get(b).add(a);
		}
		
		boolean[] visited = new boolean[N];
		int endPoint = 0;
		Deque<Integer> queue = new ArrayDeque<Integer>();
		queue.addFirst(0);
		visited[0] = true;
		
		while(queue.size() != 0){
			int q = queue.removeFirst();
			visited[q] = true;
			boolean isEnd = true;
			for(int next : G.get(q)){
				if(!visited[next]){
					visited[next] = true;
					queue.addFirst(next);
					isEnd = false;
				}
			}
			if(isEnd) endPoint = q;
		}
		
		Arrays.fill(visited, false);
		visited[endPoint] = true;
		queue.addFirst(endPoint);
		int ans = 0;
		
		while(queue.size() != 0){
			int q = queue.removeFirst();
			int num = 0;
			for(int next : G.get(q)){
				if(!visited[next]){
					visited[next] = true;
					queue.addFirst(next);
					num++;
				}
			}
			
			ans += Math.max(0, num - 1);
		}
		
		System.out.println(ans);
	}
	
	/* end solve */
	
	/* main */
	public static void main(String[] args) throws Exception {
		new Main().m();
	}
	
	void m() throws Exception {
		long S = System.currentTimeMillis();
		sc = (isDebug) ? new FastScanner(new FileInputStream(fileName)) : new FastScanner(System.in);
		//out = new PrintWriter(System.out);
		solve();
		//out.flush();
		long G = System.currentTimeMillis();
		if(isDebug){
			System.out.println("---Debug---");
			System.out.printf("%8d ms", (G-S));
		}
	}
	/* end main */
}
/* end Main */

class Pair{
	int to; int from; long cost;
	public Pair(int t, int f, long c){
		to = t; from = f; cost = c;
	}
}

class FastScanner {
    private InputStream in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    public FastScanner(InputStream in) {
		this.in = in;
	}
    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;
    }
    public boolean hasNext() {
    	while(hasNextByte() && !isPrintableChar(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 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 double nextDouble() {
    	return Double.parseDouble(next());
    }
}
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