oj.uz

답안 #848528

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
848528 2023-09-12T20:32:42 Z qthang2k11 Chase (CEOI17_chase) C++17
20 / 100
 411 ms 524288 KB 
#include <bits/stdc++.h>
using namespace std;

using ll = long long;

const int N = 1e5 + 5;

template<class X, class Y>
inline void maxi(X &x, Y y) {
	if (x < y) x = y;
}

vector<int> g[N];
int n, k, a[N];
ll s[N];

ll ans = 0, INF;

struct Node {
	ll val[101][2];

	Node() {
		memset(val, -63, sizeof val);
	}

	void maxi_(const Node &other) {
		for (int i = 0; i <= k; i++)
			for (int j = 0; j < 2; j++)
				maxi(val[i][j], other.val[i][j]);
	}

	void deal(const Node &other, const int &x, const int &y) { // update from y to x
		for (int i = 0; i <= k; i++) {
			for (int j = 0; j < 2; j++) {
				ll cur = other.val[i][j];
				if (i < k) {
					if (j) maxi(val[i + 1][1], cur + s[x] - a[y]);
					else maxi(val[i + 1][1], cur + s[x] - a[y]);
				}
				maxi(val[i][0], cur);
			}
		}
	}

	Node deal_(const int &x, const int &y) { // update from y to x
		Node ans;
		for (int i = 0; i <= k; i++) {
			for (int j = 0; j < 2; j++) {
				ll cur = val[i][j];
				if (i < k) {
					if (j) maxi(ans.val[i + 1][1], cur + s[x] - a[y]);
					else maxi(ans.val[i + 1][1], cur + s[x] - a[y]);
				}
				maxi(ans.val[i][0], cur);
			}
		}
		return ans;
	}

	ll res() const {
		ll ans = 0;
		for (int i = 0; i <= k; i++)
			for (int j = 0; j < 2; j++)
				maxi(ans, val[i][j]);
		return ans;
	}
};

vector<Node> suf[N];
Node dp[N];

void dfs_init(int x, int p) {
	for (int i = g[x].size() - 1; i >= 0; i--) {
		int y = g[x][i];
		if (y != p) continue;
		swap(g[x][i], g[x].back());
		g[x].pop_back();
	}
	for (int y: g[x]) dfs_init(y, x);
}

void dfs(int x) {
	suf[x].resize(g[x].size());
	for (int y: g[x]) dfs(y);
	for (int o = g[x].size(), i = o - 1; i >= 0; i--) {
		int y = g[x][i];
		auto &p = suf[x][i];
		if (i < o - 1) p.maxi_(suf[x][i + 1]);
		p.deal(dp[y], x, y);
	}
	if (!g[x].empty()) dp[x] = suf[x][0];
	// else {
		maxi(dp[x].val[0][0], 0);
		if (k > 0) maxi(dp[x].val[1][1], s[x]);
	// }
	maxi(ans, dp[x].res());
}

Node pref;
void dfs_reroot(int x, Node down) {
	maxi(down.val[0][0], 0);
	if (k > 0) maxi(down.val[1][1], s[x]);
	maxi(ans, down.res());
	pref = Node();
	for (int i = 0, o = g[x].size(); i < o; i++) {
		int y = g[x][i];
		Node cur = down;
		if (i > 0) cur.maxi_(pref);
		pref.deal(dp[y], x, y);
		if (i + 1 < o) cur.maxi_(suf[x][i + 1]);
		dfs_reroot(y, cur.deal_(y, x));
	}
}

int32_t main() {
	cin.tie(0)->sync_with_stdio(0); 
	cin >> n >> k;
	for (int i = 1; i <= n; i++)
		cin >> a[i];
	for (int i = 1; i < n; i++) {
		int x, y;
		cin >> x >> y;
		g[x].emplace_back(y);
		g[y].emplace_back(x);
	}
	for (int x = 1; x <= n; x++) {
		for (int y: g[x])
			s[x] += a[y];
	}
	dfs_init(1, 0);
	dfs(1);
	dfs_reroot(1, Node());
	cout << ans;
	return 0;
}

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 21 ms 164440 KB Output is correct
2 Correct 20 ms 164444 KB Output is correct
3 Correct 22 ms 164444 KB Output is correct
4 Correct 21 ms 164436 KB Output is correct
5 Correct 20 ms 164444 KB Output is correct
6 Correct 21 ms 164396 KB Output is correct

Subtask #2
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 21 ms 164440 KB Output is correct
2 Correct 20 ms 164444 KB Output is correct
3 Correct 22 ms 164444 KB Output is correct
4 Correct 21 ms 164436 KB Output is correct
5 Correct 20 ms 164444 KB Output is correct
6 Correct 21 ms 164396 KB Output is correct
7 Correct 26 ms 168272 KB Output is correct
8 Correct 24 ms 168276 KB Output is correct
9 Correct 23 ms 165968 KB Output is correct
10 Incorrect 24 ms 165972 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #3
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 411 ms 524288 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #4
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 21 ms 164440 KB Output is correct
2 Correct 20 ms 164444 KB Output is correct
3 Correct 22 ms 164444 KB Output is correct
4 Correct 21 ms 164436 KB Output is correct
5 Correct 20 ms 164444 KB Output is correct
6 Correct 21 ms 164396 KB Output is correct
7 Correct 26 ms 168272 KB Output is correct
8 Correct 24 ms 168276 KB Output is correct
9 Correct 23 ms 165968 KB Output is correct
10 Incorrect 24 ms 165972 KB Output isn't correct
11 Halted 0 ms 0 KB -