제출 #738415

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
738415		GrindMachine	Museum (CEOI17_museum)	C++17	100 / 100	666 ms	785308 KiB

museum

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e4 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
const int K = 1e4 + 5;

vector<pii> adj[N];
vector<int> subsiz(N);
int dp[N][K][2];
int dp2[K][2], dp3[K][2];
int k;

void dfs1(int u, int p) {
    subsiz[u] = 1;

    for (auto [v, w] : adj[u]) {
        if (v == p) conts;
        dfs1(v, u);
        subsiz[u] += subsiz[v];
    }
}

void dfs2(int u, int p) {
    for (auto [v, w] : adj[u]) {
        if (v == p) conts;
        dfs2(v, u);
    }

    dp[u][1][1] = 0;
    int curr_siz = 1;

    for (auto [v, w] : adj[u]) {
        if (v == p) conts;

        rev(j1, curr_siz, 1) {
            rep1(j2, subsiz[v]) {
                amin(dp[u][j1 + j2][1], dp[u][j1][1] + dp[v][j2][1] + 2 * w);
            }
        }

        curr_siz += subsiz[v];
    }

    memset(dp2, 0x3f, sizeof dp2);
    memset(dp3, 0x3f, sizeof dp3);
    dp2[1][0] = 0;

    curr_siz = 1;

    for (auto [v, w] : adj[u]) {
        if (v == p) conts;

        rev(j1, curr_siz, 1) {
            rep1(j2, subsiz[v]) {
                rep(t1, 2) {
                    rep(t2, 2) {
                        int t3 = t1 + (t2 ^ 1);
                        if (t3 >= 2) conts;

                        int cost = dp[v][j2][t2];
                        if (t2) cost += 2 * w;
                        else cost += w;

                        amin(dp3[j1 + j2][t3], dp2[j1][t1] + cost);
                    }
                }
            }
        }

        curr_siz += subsiz[v];

        rep1(j, curr_siz) {
            rep(t, 2) {
                amin(dp2[j][t], dp3[j][t]);
                dp3[j][t] = inf1;
            }
        }
    }

    rep1(j, curr_siz) {
        dp[u][j][0] = min(dp2[j][0], dp2[j][1]);
    }
}

void solve(int test_case)
{
    int n, r; cin >> n >> k >> r;
    rep1(i, n - 1) {
        int u, v, w; cin >> u >> v >> w;
        adj[u].pb({v, w}), adj[v].pb({u, w});
    }

    memset(dp, 0x3f, sizeof dp);

    dfs1(r, -1);
    dfs2(r, -1);

    int ans = dp[r][k][0];
    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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