Submission #468332

#	Time	Username	Problem	Language	Result	Execution time	Memory
468332		Vladth11	Museum (CEOI17_museum)	C++14	100 / 100	329 ms	180804 KiB

museum

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "
#pragma GCC optimize("Ofast,unroll-loops")

using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <long double, pii> muchie;
typedef tree <ll, null_type, less_equal <ll>, rb_tree_tag, tree_order_statistics_node_update> OST;

const ll NMAX = 10001;
const ll INF = (1LL << 60);
const ll HALF = (1LL << 59);
const ll MOD = 30013;
const ll BLOCK = 318;
const ll base = 31;
const ll nr_of_bits = 21;

int dp[NMAX][NMAX][2];
int n, k, root;
vector <pii> v[NMAX];
int sz[NMAX];

void DFS(int node, int p) {
    int i;
    dp[node][1][0] = dp[node][1][1] = 0;
    sz[node] = 1;
    for(auto x : v[node]) {
        if(x.first == p)
            continue;
        DFS(x.first, node);
        sz[node] += sz[x.first];
    }
    for(i = 2; i <= min(k, sz[node]); i++) {
        dp[node][i][0] = dp[node][i][1] = 1e9;
    }
    int sum = 1;

    for(auto x : v[node]) {
        if(x.first == p)
            continue;
        for(int total = min(k, sum); total >= 1; total--) {
            //debugs(total);
            for(int subtree = 1; subtree <= min(k - total, sz[x.first]); subtree++) {
                dp[node][total + subtree][0] = min(dp[node][total][0] + dp[x.first][subtree][0] + x.second * 2, dp[node][total + subtree][0]);
                dp[node][total + subtree][1] = min(dp[node][total][1] + dp[x.first][subtree][0] + x.second * 2, dp[node][total + subtree][1]);
                dp[node][total + subtree][1] = min(dp[node][total][0] + dp[x.first][subtree][1] + x.second, dp[node][total + subtree][1]);
            }
        }

        sum += sz[x.first];
    }
}

int main() {
    int i;
    cin >> n >> k >> root;
    for(i = 1; i < n; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        v[a].push_back({b, c});
        v[b].push_back({a, c});
    }
    DFS(root, 0);
    cout << dp[root][k][1];
    return 0;
}

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