[20250509] BOJ / D5 / Confuzzle / 권혁준

Author: oncsr

khj20006/202505/09 BOJ D5 Confuzzle.md

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+```cpp
+#include <iostream>
+#include <vector>
+#include <map>
+#include <utility>
+#include <algorithm>
+using namespace std;
+
+int N, INF = 1e9 + 7, ans = INF, C[100001]{};
+vector<vector<int>> V(100001);
+map<int, pair<int, int>> M[100001]{};
+
+void dfs(int n, int p) {
+	for (int i : V[n]) if (i != p) {
+		dfs(i, n);
+		C[i]++;
+		if (M[i].size() > M[n].size()) swap(M[i], M[n]), swap(C[i], C[n]);
+		for (auto[c, d] : M[i]) {
+			auto[fir, sec] = d;
+			if (M[n].find(c) == M[n].end()) M[n][c] = { fir + C[i] - C[n], sec + C[i] - C[n] };
+			else {
+				if (fir + C[i] < M[n][c].first + C[n]) M[n][c].second = M[n][c].first, M[n][c].first = fir + C[i] - C[n];
+				else if (fir < M[n][c].second) M[n][c].second = fir + C[i] - C[n];
+				if (sec < M[n][c].second) M[n][c].second = sec + C[i] - C[n];
+			}
+			ans = min(ans, M[n][c].first + M[n][c].second + 2*C[n]);
+		}
+		M[i] = map<int, pair<int, int>>();
+	}
+}
+
+int main() {
+	cin.tie(0)->sync_with_stdio(0);
+
+	cin >> N;
+	for (int i = 1, a; i <= N; i++) {
+		cin >> a;
+		M[i][a] = { 0,INF };
+	}
+	for (int i = 1, a, b; i < N; i++) {
+		cin >> a >> b;
+		V[a].push_back(b);
+		V[b].push_back(a);
+	}
+
+	dfs(1, 0);
+	cout << ans;
+
+}
+```