[20250404] BOJ / P3 / 정원 정리 / 권혁준

Author: oncsr

khj20006/202504/04 BOJ P3 정원 정리.md

@@ -0,0 +1,94 @@
+```java
+
+import java.util.*;
+import java.io.*;
+
+class Main {
+	
+	// IO field
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	static StringTokenizer st = new StringTokenizer("");
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static String nextToken() throws Exception {
+		while(!st.hasMoreTokens()) nextLine();
+		return st.nextToken();
+	}
+	static int nextInt() throws Exception { return Integer.parseInt(nextToken()); }
+	static long nextLong() throws Exception { return Long.parseLong(nextToken()); }
+	static double nextDouble() throws Exception { return Double.parseDouble(nextToken()); }
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+	
+	// Additional field
+	
+	static int N, M;
+	static boolean[][] edge;
+	static int[] sub;
+	static int[][] dp;
+	static final int INF = 1234;
+	
+	public static void main(String[] args) throws Exception {
+			
+		ready();
+		solve();
+	
+		bwEnd();
+		
+	}
+	
+	static void ready() throws Exception{
+		
+		N = nextInt();
+		M = nextInt();
+		edge = new boolean[N+1][N+1];
+		sub = new int[N+1];
+		for(int i=1;i<N;i++) {
+			int a = nextInt(), b = nextInt();
+			edge[a][b] = edge[b][a] = true;
+		}
+		dp = new int[N+1][];
+		
+	}
+	
+	static void solve() throws Exception{
+		
+		pre(1,0);
+		dfs(1,0);
+		int ans = dp[1][M];
+		for(int i=2;i<=N;i++) if(sub[i] >= M) ans = Math.min(ans, dp[i][M] + 1);
+		bw.write(ans + "\n");
+		
+	}
+	
+	static void pre(int n, int p) {
+		sub[n] = 1;
+		for(int i=1;i<=N;i++) if(edge[n][i] && i != p) {
+			pre(i,n);
+			sub[n] += sub[i];
+		}
+	}
+	
+	static void dfs(int n, int p) {
+		
+		dp[n] = new int[sub[n]+1];
+		Arrays.fill(dp[n], INF);
+		dp[n][1] = 0;
+		dp[n][0] = 1;
+		for(int i=1;i<=N;i++) if(edge[n][i] && i != p) {
+			dfs(i,n);
+			int[] ndp = new int[sub[n]+1];
+			Arrays.fill(ndp, INF);
+			for(int k=0;k<=sub[i];k++) {
+				for(int g=sub[n];g>=k;g--) {
+					ndp[g] = Math.min(ndp[g], dp[i][k] + dp[n][g-k]);
+				}
+			}
+			dp[n] = ndp;
+		}
+		if(n != 1) dp[n][0] = 1;
+	}
+	
+}
+
+```