Submission #1252180

#	Time	Username	Problem	Language	Result	Execution time	Memory
1252180		rayan_bd	Museum (CEOI17_museum)	C++20	0 / 100	526 ms	1114112 KiB

museum

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 10005;

#define int long long

const int INF = 5e18;

vector<pair<int, int>> adj[MAXN];
int dp[MAXN][MAXN][2], sz[MAXN];

int n, k, x;

void dfs(int u, int par) {
    dp[u][1][0] = dp[u][1][1] = 0;
    sz[u] = 1;
    for (auto [v, cost] : adj[u]) {
        if (v == par) continue;
        dfs(v, u);
        for(int i = sz[u]; i >= 0; --i){
            for(int j = sz[v]; j >= 0; --j){
                dp[u][i + j][0] = min(dp[u][i + j][0], dp[u][i][0] + dp[v][j][0] + cost * 2);
                dp[u][i + j][1] = min(dp[u][i + j][1], dp[u][i][1] + dp[v][j][0] + cost * 2);
                dp[u][i + j][1] = min(dp[u][i + j][1], dp[u][i][0] + dp[v][j][1] + cost);
            }
        }
        sz[u] += sz[v];
    }
}

signed main() {
	#ifndef ONLINE_JUDGE
	freopen("input.in", "r", stdin);
	freopen("output.out", "w", stdout);
	#endif
	ios_base::sync_with_stdio(0);
	cin.tie(nullptr); cout.tie(nullptr);


    cin >> n >> k >> x;
    for (int i = 1; i < n; ++i) {
        int a, b, c;
        cin >> a >> b >> c;
        adj[a].emplace_back(b, c);
        adj[b].emplace_back(a, c);
    }

    memset(dp, 0x3f, sizeof(dp));

    dfs(x, -1);

    int answer = min(dp[x][k][0], dp[x][k][1]);
    cout << dp[x][k][1] << '\n';

    return 0;
}

Compilation message (stderr)

museum.cpp: In function 'int main()':
museum.cpp:34:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |         freopen("input.in", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
museum.cpp:35:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |         freopen("output.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 20
• Subtask 2: 0 / 25
• Subtask 3: 0 / 35
• Subtask 4: 0 / 20