Submission #975311

#	Time	Username	Problem	Language	Result	Execution time	Memory
975311		dosts	Museum (CEOI17_museum)	C++17	20 / 100	1643 ms	827728 KiB

museum

//Dost SEFEROĞLU
#pragma GCC optimize("O3,unroll-loops,Ofast")
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " << 
#define vi vector<int>
const int N = 5e3+100,inf = 1e18,MOD = 998244353;


int dp[N][2][N];
vector<pii> edges[N];
vi sz(N);

int szs(int node,int p) {
    sz[node] = 1;
    for (auto it : edges[node]) if (it.ff != p) sz[node]+=szs(it.ff,node);
    return sz[node];
}

int K;
void compute(int node,int p) {
    int curmx = 1;
    for (auto it : edges[node]) {
        if (it.ff == p) continue;
        int u = it.ff,w = it.ss;
        compute(u,node);
        curmx+=sz[u];
        for (int i=curmx;i>=2;i--) {
            for (int j=max(0ll,-curmx+sz[u]+i);j<=min(i,sz[u]);j++) {
                dp[node][0][i] = min(dp[node][0][i],dp[node][0][i-j] + dp[u][1][j]+ 2*w);
                dp[node][1][i] = min(dp[node][1][i],dp[node][1][i-j] + dp[u][1][j]+ 2*w);
                dp[node][0][i] = min(dp[node][0][i],dp[node][1][i-j] + dp[u][0][j] + w); 
            }
        }
    }
}

void solve() {
    int n,x;
    cin >> n >> K >> x;
    for (int i=1;i<=n-1;i++) {
        int u,v,w;
        cin >> u >> v >> w;
        edges[u].push_back({v,w});
        edges[v].push_back({u,w});
    }
    for (int i=1;i<=n;i++) for(int j=0;j<2;j++) for (int k=2;k<=n;k++) dp[i][j][k] = inf;
    szs(x,x);
    compute(x,x);
    cout << dp[x][0][K] << endl;
}

                             
signed main() { 
    ios_base::sync_with_stdio(0);
    #ifdef Dodi
        freopen("in.txt","r",stdin);
        freopen("out.txt","w",stdout);
    #endif
    int t = 1;
    //cin >> t; 
    while (t --> 0) solve();
}

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