제출 #938804

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
938804		Whisper	Museum (CEOI17_museum)	C++17	100 / 100	491 ms	784976 KiB

museum

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

//#define int long long
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define Lg(x) 31 - __builtin_clz(x)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)

constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 1e4 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void setupIO(){
    #define name "Whisper"
    //Phu Trong from Nguyen Tat Thanh High School for gifted student
    srand(time(NULL));
    cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    cout << fixed << setprecision(10);
}

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }
int numNode, staNode, K;
vector<pair<int, int>> G[MAX];

int dp[MAX][MAX][2];
int sz[MAX];
/*
    0. start a path at u go to u's subtree and end at u
    1. start a path at u go to u's subtree and end at a node in subtree
*/
void dfs(int u, int p = -1){
    sz[u] = 1;
    for (pair<int, int>& x : G[u]){
        int v = x.first, w = x.second;
        if(v ^ p){
            dfs(v, u);
            for (int k = sz[u]; k >= 0; --k){
                for (int l = sz[v]; l >= 0; --l){
                    minimize(dp[u][l + k][0], dp[v][l][0] + dp[u][k][0] + 2 * w);
                    minimize(dp[u][l + k][1], dp[v][l][0] + dp[u][k][1] + 2 * w);
                    minimize(dp[u][l + k][1], dp[v][l][1] + dp[u][k][0] + w);
                }
            }
            sz[u] += sz[v];
        }
    }
}
void Whisper(){
    cin >> numNode >> K >> staNode;
    for (int i = 1; i < numNode; ++i){
        int u, v, w; cin >> u >> v >> w;
        G[u].emplace_back(v, w);
        G[v].emplace_back(u, w);
    }
    for (int i = 1; i <= numNode; ++i)
        for (int j = 2; j <= numNode; ++j)
            dp[i][j][0] = dp[i][j][1] = INF;
    dfs(staNode);

    cout << min(dp[staNode][K][1], dp[staNode][K][0]);
}


signed main(){
    setupIO();
    int Test = 1;
//    cin >> Test;
    for ( int i = 1 ; i <= Test ; i++ ){
        Whisper();
        if (i < Test) cout << '\n';
    }
}

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