oj.uz

답안 #1088947

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1088947 2024-09-15T15:43:24 Z SamNguyen Museum (CEOI17_museum) C++14
80 / 100
 3000 ms 473332 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];
	for (int x = 0; x <= min(K, sz[u]); x++) 
		g[x][false] = g[x][true] = INF;

	g[0][true ] = 0;
	g[0][false] = 0;

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

		for (int s = min(K, sz[u]); s >= 0; s--) 
		for (int x = 0, y = s; y >= 1; x++, 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:96:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |   freopen(INPFILE, "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
museum.cpp:97:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   97 |   freopen(OUTFILE, "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 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 45 ms 90448 KB Output is correct
2 Correct 54 ms 90448 KB Output is correct
3 Correct 95 ms 90708 KB Output is correct
4 Correct 69 ms 90280 KB Output is correct
5 Correct 59 ms 90164 KB Output is correct

Subtask #3
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 45 ms 90448 KB Output is correct
2 Correct 54 ms 90448 KB Output is correct
3 Correct 95 ms 90708 KB Output is correct
4 Correct 69 ms 90280 KB Output is correct
5 Correct 59 ms 90164 KB Output is correct
6 Correct 49 ms 90192 KB Output is correct
7 Correct 98 ms 90448 KB Output is correct
8 Correct 126 ms 90456 KB Output is correct
9 Correct 126 ms 90456 KB Output is correct
10 Correct 124 ms 90456 KB Output is correct

Subtask #4
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 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 45 ms 90448 KB Output is correct
7 Correct 54 ms 90448 KB Output is correct
8 Correct 95 ms 90708 KB Output is correct
9 Correct 69 ms 90280 KB Output is correct
10 Correct 59 ms 90164 KB Output is correct
11 Correct 49 ms 90192 KB Output is correct
12 Correct 98 ms 90448 KB Output is correct
13 Correct 126 ms 90456 KB Output is correct
14 Correct 126 ms 90456 KB Output is correct
15 Correct 124 ms 90456 KB Output is correct
16 Correct 152 ms 160548 KB Output is correct
17 Correct 1071 ms 473332 KB Output is correct
18 Correct 2337 ms 160916 KB Output is correct
19 Execution timed out 3036 ms 160700 KB Time limit exceeded
20 Halted 0 ms 0 KB -