AuthorSol.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Random;
import java.util.StringTokenizer;

public class AuthorSol {
	
	static ArrayList<Integer>[] adj;
	static int res = 0;
	
	public static void main(String[] args) {
		FastScanner fs = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);
		int T = 1;
		T = fs.nextInt();
		for (int tc = 1; tc <= T; tc++) {
			int n = fs.nextInt(), k = fs.nextInt();
			adj = new ArrayList[n];
			for (int i = 0; i < n; i++) {
				adj[i] = new ArrayList<>();
			}
			for (int i = 0; i < n - 1; i++) {
				int u = fs.nextInt(), v = fs.nextInt();
				--u; --v;
				adj[u].add(v);
				adj[v].add(u);
			}
			int low = 1, high = n / (k + 1) + 1;
			while (high - low > 1) {
				int mid = (low + high) / 2;
				if (check(mid, k)) {
					low = mid;
				} else {
					high = mid;
				}
			}
			System.out.println(low);
		}
		out.close();
	}
	
	static boolean check(int x, int k) {
		res = 0;
		int t = dfs(0, 0, x);
		return (res > k || (t >= x && res == k));
	}
	
	static int dfs(int u, int parent, int x) {
		int sz = 1;
		for (int v : adj[u]) {
			if (v == parent) {
				continue;
			}
			sz += dfs(v, u, x);
		}
		if (sz >= x && parent != u) {
			res++;
			sz = 0;
		}
		return sz;
	}
	
	static final Random rnd = new Random();
	static void shuffleSort(int[] a) { //change this
		int n = a.length;
		for (int i = 0; i < n; i++) {
			int newInd = rnd.nextInt(n);
			int temp = a[newInd]; //change this
			a[newInd] = a[i];
			a[i] = temp;
		}
		Arrays.sort(a);
	}
	
	static class FastScanner {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer("");
		
		String next() {
			while (!st.hasMoreTokens()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}
		
		int nextInt() {
			return Integer.parseInt(next());
		}
		
		int[] readArray(int n) {
			int[] a = new int[n];
			for (int i = 0; i < n; i++) {
				a[i] = nextInt();
			}
			return a;
		}
		
		long[] readLongArray(int n) {
			long[] a = new long[n];
			for (int i = 0; i < n; i++) {
				a[i] = nextLong();
			}
			return a;
		}
		
		double[] readDoubleArray(int n) {
			double[] a = new double[n];
			for (int i = 0; i < n; i++) {
				a[i] = nextDouble();
			}
			return a;
		}
		
		long nextLong() {
			return Long.parseLong(next());
		}
		
		double nextDouble() {
			return Double.parseDouble(next());
		}
		
		String nextLine() {
			String str = "";
			try {
				if (st.hasMoreTokens()) {
					str = st.nextToken("\n");
				} else {
					str = br.readLine();
				}
			} catch(IOException e) {
				e.printStackTrace();
			}
			return str;
		}
	}
}