제출 #884451

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
884451		Peter2017	Museum (CEOI17_museum)	C++14	0 / 100	8 ms	3676 KiB

museum

#include <bits/stdc++.h>
#define fi first
#define se second
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pill pair<int,ll>
#define mem(a, b) memset(a, b, sizeof(a))
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define name "test"

using namespace std;

const int N = 1e4 + 5;
const int mod = 1e9 + 7;
const ll oo = 1e18;

template <typename T1, typename T2> bool maxi(T1 &a, T2 b){if (a < b){a = b; return 1;} return 0;}
template <typename T1, typename T2> bool mini(T1 &a, T2 b){if (a > b){a = b; return 1;} return 0;}

int n;
int rooms;
int root;
int sz[N];
int g[N], g2[N];
vector <int> f[N];
vector <int> longest[N];
vector <pii> adj[N];

void load(){
    cin.tie(0)->sync_with_stdio(0);
    if (fopen(name".inp", "r")){
        freopen(name".inp", "r", stdin);
        freopen(name".out", "w", stdout);
    }
}

void input(){
    cin >> n >> rooms >> root;
    for (int i = 1; i < n; i++){
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }
}

void dfs_sz(int u, int pre){
    sz[u] = 1;
    for (auto v : adj[u]) if (v.fi != pre){
        dfs_sz(v.fi, u);
        sz[u] += sz[v.fi];
    }
    f[u].resize(sz[u] + 1, mod);
    longest[u].resize(sz[u] + 1, 0);
}

void combine(int u, int v, int w){
    for (int i = 0; i <= min(rooms, sz[u] + sz[v]); i++)
        g[i] = mod;
    for (int i = 1; i <= min(rooms, sz[u]); i++)
        for (int j = 0; j <= min(rooms - i, sz[v]); j++){
            if (mini(g[i + j], f[u][i] + f[v][j] + w * 2))
                g2[i + j] = max(longest[u][i], longest[v][j] + w);
        }
    for (int i = 0; i <= min(rooms, sz[u] + sz[v]); i++)
        if (mini(f[u][i], g[i]))
            longest[u][i] = g2[i];
}

void dfs(int u, int pre){
    sz[u] = 1;
    f[u][1] = 0;
    for (auto it : adj[u]){
        int v = it.fi;
        int w = it.se;
        if (v != pre){
            dfs(v, u);
            combine(u, v, w);
            sz[u] += sz[v];
        }
    }
}

void solve(){
    dfs_sz(root, root);
    dfs(root, root);
    cout << f[root][rooms] - longest[root][rooms];
}

int main(){
    load();
    input();
    solve();
}

컴파일 시 표준 에러 (stderr) 메시지

museum.cpp: In function 'void load()':
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(name".inp", "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(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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