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답안 #1088951

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1088951 2024-09-15T15:54:17 Z SamNguyen Museum (CEOI17_museum) C++14
80 / 100
 3000 ms 784128 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, cum_size); 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 856 KB Output is correct
2 Correct 1 ms 856 KB Output is correct
3 Correct 0 ms 860 KB Output is correct
4 Correct 1 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 44 ms 90452 KB Output is correct
2 Correct 45 ms 90272 KB Output is correct
3 Correct 73 ms 90704 KB Output is correct
4 Correct 59 ms 90456 KB Output is correct
5 Correct 50 ms 90196 KB Output is correct

Subtask #3
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 44 ms 90452 KB Output is correct
2 Correct 45 ms 90272 KB Output is correct
3 Correct 73 ms 90704 KB Output is correct
4 Correct 59 ms 90456 KB Output is correct
5 Correct 50 ms 90196 KB Output is correct
6 Correct 41 ms 90196 KB Output is correct
7 Correct 79 ms 90684 KB Output is correct
8 Correct 38 ms 90448 KB Output is correct
9 Correct 35 ms 90452 KB Output is correct
10 Correct 36 ms 90452 KB Output is correct

Subtask #4
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 856 KB Output is correct
2 Correct 1 ms 856 KB Output is correct
3 Correct 0 ms 860 KB Output is correct
4 Correct 1 ms 860 KB Output is correct
5 Correct 0 ms 860 KB Output is correct
6 Correct 44 ms 90452 KB Output is correct
7 Correct 45 ms 90272 KB Output is correct
8 Correct 73 ms 90704 KB Output is correct
9 Correct 59 ms 90456 KB Output is correct
10 Correct 50 ms 90196 KB Output is correct
11 Correct 41 ms 90196 KB Output is correct
12 Correct 79 ms 90684 KB Output is correct
13 Correct 38 ms 90448 KB Output is correct
14 Correct 35 ms 90452 KB Output is correct
15 Correct 36 ms 90452 KB Output is correct
16 Correct 116 ms 160784 KB Output is correct
17 Correct 634 ms 473172 KB Output is correct
18 Correct 1540 ms 160852 KB Output is correct
19 Correct 107 ms 160596 KB Output is correct
20 Correct 106 ms 160684 KB Output is correct
21 Execution timed out 3106 ms 784128 KB Time limit exceeded
22 Halted 0 ms 0 KB -