Submission #479781

#	Time	Username	Problem	Language	Result	Execution time	Memory
479781		sam571128	Fireworks (APIO16_fireworks)	C++17	26 / 100	28 ms	2456 KiB

fireworks

#include <bits/stdc++.h>

#define int long long
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

using namespace std;

const int N = 605, M = 305;
vector<pair<int,int>> adj[N];

int dp[N][M], val[N][M];

void dfs(int u, int p){
    if(adj[u].size()==1&&u!=1){
        dp[u][0] = 0;
    }

    for(auto [v,w] : adj[u]){
        if(v == p) continue;
        dfs(v,u);
        fill(val[u],val[u]+M,1e18);
        for(int i = 0;i < M;i++){
            for(int j = 0;j <= i;j++){
                val[u][i] = min(val[u][i], abs(w-(i-j))+dp[v][j]);
            }
        }

        for(int i = 0;i < M;i++){
            if(dp[u][i]==1e18) dp[u][i] = 0;
            dp[u][i] += val[u][i];
        }
    }
}

signed main(){
    //fastio
    int n,m;
    cin >> n >> m;
    if(n==1){
        vector<int> tmp;
        for(int i = 0;i < m;i++){
            int a,x;
            cin >> a >> x;
            tmp.push_back(x);
        }

        sort(tmp.begin(),tmp.end());

        int to = tmp[tmp.size()/2];
        int ans = 0;

        for(auto x : tmp){
            ans += abs(x-to);
        }

        cout << ans << "\n";
    }else{
        for(int i = 2;i <= n;i++){
            int p,x;
            cin >> p >> x;
            adj[p].push_back({i,x});
            adj[i].push_back({p,x});
        }
        for(int i = 1;i <= m;i++){
            int p,x;
            cin >> p >> x;
            adj[p].push_back({i+n,x});
            adj[i+n].push_back({p,x});
        }

        fill(&dp[0][0],&dp[N-1][M-1],1e18);


        dfs(1,1);


        cout << *min_element(dp[1],dp[1]+M) << "\n";
    }
}

• Subtask 1: 7 / 7
• Subtask 2: 19 / 19
• Subtask 3: 0 / 29
• Subtask 4: 0 / 45