oj.uz

답안 #848520

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
848520 2023-09-12T20:20:25 Z qthang2k11 Chase (CEOI17_chase) C++17
40 / 100
 357 ms 524288 KB 
#include <bits/stdc++.h>
using namespace std;

#ifdef LOCAL
#undef LOCAL
#endif

#ifndef LOCAL
#define fprintf(...) {}
#endif

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) maxi(val[i + 1][1], cur + s[x] - a[y] + (j ? a[y] : 0));
				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 + 1][1], cur + s[x] - a[y] - (j ? a[x] : 0));
				}
				// maxi(val[i][0], cur + (j ? a[y] : 0));
				maxi(val[i][0], cur/* + (j ? a[x] : 0)*/);
			}
		}
	}

	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) maxi(ans.val[i + 1][1], cur + s[x] - a[y] + (j ? a[y] : 0));
				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 + 1][1], cur + s[x] - a[y] - (j ? a[x] : 0));
				}
				// maxi(ans.val[i][0], cur + (j ? a[y] : 0));
				maxi(ans.val[i][0], cur/* + (j ? a[x] : 0)*/);
			}
		}
		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;
	}

	void debug(int x) {
		#ifndef LOCAL
		return;
		#endif
		cerr << string(15, '=') << '\n';
		for (int i = 0; i <= k; i++)
			for (int j = 0; j < 2; j++)
				fprintf(stderr, "dp[%d][%d][%d] = %lld\n", x, i, j, val[i][j]);
		cerr << string(15, '=') << '\n';
	}
};

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

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());
	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[x][i - 1]);
		if (i + 1 < o) cur.maxi_(suf[x][i + 1]);
		dfs_reroot(y, cur.deal_(y, x));
	}
}

int32_t main() {
#ifndef LOCAL
	cin.tie(0)->sync_with_stdio(0); // ====================================================
#endif
//	freopen("chase.03.01.in", "r", stdin);
	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];
		fprintf(stderr, "s[%d] = %lld\n", x, s[x]);
	}
//	cerr << "?\n";
	dfs_init(1, 0);
//	cerr << "?\n";
	// return 0;
	dfs(1);
//	cerr << "?\n";
	dfs_reroot(1, Node()); // ============================================================
//	cerr << "?\n";
	cout << ans;
	return 0;
}

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 166744 KB Output is correct
2 Correct 22 ms 166632 KB Output is correct
3 Correct 21 ms 166736 KB Output is correct
4 Correct 21 ms 166768 KB Output is correct
5 Correct 21 ms 166732 KB Output is correct
6 Correct 21 ms 166744 KB Output is correct

Subtask #2
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 166744 KB Output is correct
2 Correct 22 ms 166632 KB Output is correct
3 Correct 21 ms 166736 KB Output is correct
4 Correct 21 ms 166768 KB Output is correct
5 Correct 21 ms 166732 KB Output is correct
6 Correct 21 ms 166744 KB Output is correct
7 Correct 28 ms 172380 KB Output is correct
8 Correct 31 ms 172376 KB Output is correct
9 Correct 23 ms 169980 KB Output is correct
10 Correct 25 ms 170076 KB Output is correct
11 Correct 23 ms 169820 KB Output is correct
12 Correct 23 ms 169828 KB Output is correct

Subtask #3
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 357 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 23 ms 166744 KB Output is correct
2 Correct 22 ms 166632 KB Output is correct
3 Correct 21 ms 166736 KB Output is correct
4 Correct 21 ms 166768 KB Output is correct
5 Correct 21 ms 166732 KB Output is correct
6 Correct 21 ms 166744 KB Output is correct
7 Correct 28 ms 172380 KB Output is correct
8 Correct 31 ms 172376 KB Output is correct
9 Correct 23 ms 169980 KB Output is correct
10 Correct 25 ms 170076 KB Output is correct
11 Correct 23 ms 169820 KB Output is correct
12 Correct 23 ms 169828 KB Output is correct
13 Runtime error 357 ms 524288 KB Execution killed with signal 9
14 Halted 0 ms 0 KB -