Merge pull request #329 from AlgorithmWithGod/khj20006

[20250508] BOJ / P1 / 고양이 소개팅 / 권혁준

Author: ShinHeeEul

khj20006/202505/08 BOJ P1 고양이 소개팅.md

@@ -0,0 +1,61 @@
+```cpp
+#include <iostream>
+#include <vector>
+#include <map>
+#include <algorithm>
+using namespace std;
+using ll = long long;
+
+int N;
+ll C[200001]{}, H[200001]{}, par[200001]{}, dist[200001]{}, V[200001]{};
+map<ll, ll> M[200001]{};
+vector<vector<pair<int, ll>>> T(200001);
+
+ll ans = 0;
+
+void dfs(int n) {
+	for (auto[i, c] : T[n]) {
+		dfs(i);
+		V[i] += c;
+		if (M[i].size() > M[n].size()) swap(M[i], M[n]), swap(V[i], V[n]);
+		for (auto[d, x] : M[i]) M[n][d + V[i] - V[n]] += x;
+		M[i] = map<ll, ll>();
+	}
+	if (H[n] != -1) {
+		H[n] -= V[n];
+		auto it = M[n].upper_bound(H[n]);
+		if (it == M[n].begin()) return;
+		it--;
+		vector<ll> er;
+		while (C[n] > 0) {
+			ll am = min(it->second, C[n]);
+			C[n] -= am;
+			ans += am;
+			M[n][it->first] -= am;
+			if (am == it->second) er.push_back(it->first);
+			if (it == M[n].begin()) break;
+			it--;
+		}
+		for (ll i : er) M[n].erase(i);
+	}
+}
+
+int main() {
+	cin.tie(0)->sync_with_stdio(0);
+
+	cin >> N;
+	for (int i = 1; i <= N; i++) cin >> C[i];
+	for (int i = 1; i <= N; i++) cin >> H[i];
+	for (int i = 2; i <= N; i++) cin >> par[i];
+	for (int i = 2; i <= N; i++) {
+		cin >> dist[i];
+		T[par[i]].emplace_back(i, dist[i]);
+	}
+
+	for (int i = 1; i <= N; i++) if (H[i] == -1) M[i].insert({ 0,C[i] });
+	dfs(1);
+
+	cout << ans;
+
+}
+```