oj.uz

답안 #1088949

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1088949 2024-09-15T15:53:17 Z SamNguyen Museum (CEOI17_museum) C++14
80 / 100
 3000 ms 784212 KB 
#include <bits/stdc++.h>
using namespace std;

#define INPFILE ".inp"
#define OUTFILE ".out"

const int INF = 3e8 + 7;

template <class T1, class T2>
inline bool minimise(T1 &x, T2 y) {
	if (x > y) { x = y; return true; }
	return false;
}

template <class T>
inline void minimise_pair(pair<T, T> &x, T y) {
	if (x.second > y)
		swap(x.second, y);
	if (x.first > x.second)
		swap(x.second, x.first);
}

const int MAX = 1e4 + 3;
int N, K, ROOT;
vector<pair<int, int>> adj[MAX];

void input() {
	cin >> N >> K >> ROOT;
	for (int t = N - 1; t--; ) {
		int u, v, w; cin >> u >> v >> w;
		adj[u].emplace_back(v, w);
		adj[v].emplace_back(u, w);
	}
}

int dp[2][MAX][MAX], sz[MAX];

void dfs(int u, int p) {
	sz[u] = 1;
	for (const auto &e : adj[u]) {
		int v, w;
		tie(v, w) = e;
		if (v == p) continue;
		dfs(v, u);
		sz[u] += sz[v];
	}

	static int g[MAX][2];

	g[0][true ] = 0;
	g[0][false] = 0;
	for (int s = min(K, sz[u]); s >= 1; s--) 
		g[s][true ] = g[s][false] = INF;

	int cum_size = 1;

	for (const auto &e : adj[u]) {
		int v, w;
		tie(v, w) = e;
		if (v == p) continue;

		cum_size += sz[v];

		for (int s = min(K, sz[u]); s >= 1; s--) {
			for (int y = min(s, sz[v] + 1); y >= 1; y--) {
				int x = s - y;
				minimise(g[s][true ], g[x][true ] + 2 * w + dp[true ][v][y - 1]);
				minimise(g[s][false], g[x][false] + 2 * w + dp[true ][v][y - 1]);
				minimise(g[s][false], g[x][true ] +     w + dp[false][v][y - 1]);
			}
		}
	}

	dp[true ][u][0] = 0;
	dp[false][u][0] = 0;
	for (int k = 1; k <= min(K, sz[u]); k++) {
		minimise(dp[false][u][k], g[k][false]);
		minimise(dp[true ][u][k], g[k][true ]);
	}
}

void solve() {
	if (K == 1) {
		cout << 0;
		return;
	}

	for (int t : {0, 1})
	for (int u = 0; u <= N; u++)
	for (int k = 0; k <= K; k++)
		dp[t][u][k] = INF;
	
	adj[0].emplace_back(ROOT, 0);
	dfs(0, -1);

	int ans = dp[false][0][K];
	cout << ans;
}
	
int main(void) {
	if (fopen(INPFILE, "r")) {
		freopen(INPFILE, "r", stdin);
		freopen(OUTFILE, "w", stdout);
	}
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	input();
	solve();

	return 0;
}

Compilation message

museum.cpp: In function 'int main()':
museum.cpp:102:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |   freopen(INPFILE, "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
museum.cpp:103:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |   freopen(OUTFILE, "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 860 KB Output is correct
2 Correct 0 ms 860 KB Output is correct
3 Correct 0 ms 860 KB Output is correct
4 Correct 0 ms 860 KB Output is correct
5 Correct 0 ms 860 KB Output is correct

Subtask #2
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 52 ms 90452 KB Output is correct
2 Correct 48 ms 90452 KB Output is correct
3 Correct 81 ms 90712 KB Output is correct
4 Correct 74 ms 90616 KB Output is correct
5 Correct 55 ms 90304 KB Output is correct

Subtask #3
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 52 ms 90452 KB Output is correct
2 Correct 48 ms 90452 KB Output is correct
3 Correct 81 ms 90712 KB Output is correct
4 Correct 74 ms 90616 KB Output is correct
5 Correct 55 ms 90304 KB Output is correct
6 Correct 45 ms 90384 KB Output is correct
7 Correct 99 ms 90604 KB Output is correct
8 Correct 41 ms 90452 KB Output is correct
9 Correct 43 ms 90456 KB Output is correct
10 Correct 45 ms 90508 KB Output is correct

Subtask #4
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 860 KB Output is correct
2 Correct 0 ms 860 KB Output is correct
3 Correct 0 ms 860 KB Output is correct
4 Correct 0 ms 860 KB Output is correct
5 Correct 0 ms 860 KB Output is correct
6 Correct 52 ms 90452 KB Output is correct
7 Correct 48 ms 90452 KB Output is correct
8 Correct 81 ms 90712 KB Output is correct
9 Correct 74 ms 90616 KB Output is correct
10 Correct 55 ms 90304 KB Output is correct
11 Correct 45 ms 90384 KB Output is correct
12 Correct 99 ms 90604 KB Output is correct
13 Correct 41 ms 90452 KB Output is correct
14 Correct 43 ms 90456 KB Output is correct
15 Correct 45 ms 90508 KB Output is correct
16 Correct 142 ms 160848 KB Output is correct
17 Correct 685 ms 473428 KB Output is correct
18 Correct 1632 ms 160916 KB Output is correct
19 Correct 110 ms 160868 KB Output is correct
20 Correct 114 ms 160844 KB Output is correct
21 Execution timed out 3109 ms 784212 KB Time limit exceeded
22 Halted 0 ms 0 KB -