[20250210] BOJ / 플래5 / OMOI / 권혁준

khj20006/202502/10 BOJ P5 OMOI.md

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+```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;
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static int nextInt() {return Integer.parseInt(st.nextToken());}
+	static long nextLong() {return Long.parseLong(st.nextToken());}
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+
+	// Additional field
+	static int[] C;
+	static List<Integer>[] V;
+	static int N;
+	static int[] cnt, mn;
+	static long[] sum;
+	static long ans = 0;
+
+
+	public static void main(String[] args) throws Exception {
+
+		ready();
+		solve();
+
+		bwEnd();
+	}
+
+	static void ready() throws Exception{
+
+		N = Integer.parseInt(br.readLine());
+		V = new List[N+1];
+		for(int i=1;i<=N;i++) V[i] = new ArrayList<>();
+		C = new int[N+1];
+		cnt = new int[N+1];
+		mn = new int[N+1];
+		sum = new long[N+1];
+
+		nextLine();
+		for(int i=2;i<=N;i++) V[nextInt()].add(i);
+		nextLine();
+		for(int i=2;i<=N;i++) C[i] = nextInt();
+
+	}
+
+	static void solve() throws Exception{
+
+		dfs(1);
+		bw.write(ans+"\n");
+
+	}
+
+	static void dfs(int n) {
+		mn[n] = Integer.MAX_VALUE;
+		cnt[n] = 1;
+		sum[n] = C[n];
+		int mxCnt = 0;
+		for(int i:V[n]) {
+			dfs(i);
+			cnt[n] += cnt[i];
+			sum[n] += sum[i];
+			mxCnt = Math.max(mxCnt, cnt[i]);
+			mn[n] = Math.min(mn[n], mn[i]);
+		}
+		ans += sum[n] - C[n];
+		if(mxCnt > cnt[n]-1-mxCnt) {
+			long rem = cnt[n]-1 - (cnt[n]-1-mxCnt)*2;
+			int minValue = Integer.MAX_VALUE;
+			for(int i:V[n]) {
+				if(cnt[i] == mxCnt) continue;
+				minValue = Math.min(minValue, mn[i]);
+			}
+			ans += rem * minValue;
+		}
+		else {
+			if((cnt[n]-1) % 2 != 0) {
+				ans += mn[n];
+			}
+		}
+		mn[n] = Math.min(mn[n], C[n]);
+	}
+
+}
+
+```