Submission #1288465

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288465		_callmelucian	Museum (CEOI17_museum)	C++17	100 / 100	200 ms	220968 KiB

museum

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

using ll = long long;
using ld = long double;
using pl = pair<ll,ll>;
using pii = pair<int,int>;
using tpl = tuple<int,int,int>;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const int mn = 1e4 + 1;
int dp[2][mn][mn], knap[2][mn], sz[mn], n, k, x;
vector<pii> adj[mn];

void dfs (int u, int p) {
    sz[u] = 1;
    for (auto [v, w] : adj[u])
        if (v != p) dfs(v, u), sz[u] += sz[v];
    
    knap[0][0] = knap[1][0] = 0;
    for (int i = 1; i <= sz[u]; i++)
        knap[0][i] = knap[1][i] = INT_MAX;
    
    int knapSize = 0;
    for (auto [v, w] : adj[u]) {
        if (v == p) continue;
        for (int preTake = knapSize; preTake >= 0; preTake--) {
            for (int curTake = 1; curTake <= sz[v]; curTake++) {
                int sum = preTake + curTake;
                knap[0][sum] = min(knap[0][sum], knap[0][preTake] + dp[0][v][curTake] + 2 * w);
                knap[1][sum] = min(knap[1][sum], knap[0][preTake] + dp[1][v][curTake] + w);
                knap[1][sum] = min(knap[1][sum], knap[1][preTake] + dp[0][v][curTake] + 2 * w);
            }
        }
        knapSize += sz[v];
    }

    
    for (int i = 0; i < sz[u]; i++)
        dp[0][u][i + 1] = knap[0][i], dp[1][u][i + 1] = knap[1][i];

    // cout << "dp " << u << " with size " << sz[u] << ":" << endl;
    // for (int i = 1; i <= sz[u]; i++) cout << "size " << i << ": " << dp[0][u][i] << " " << dp[1][u][i] << endl;
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n, k, x; 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);
    }
    dfs(x, -1);
    cout << dp[1][x][k] << "\n";

    return 0;
}

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