Submission #1333861

#TimeUsernameProblemLanguageResultExecution timeMemory
1333861KALARRYRoad Closures (APIO21_roads)C++20
0 / 100
131 ms63460 KiB
//chockolateman

#include<bits/stdc++.h>

using namespace std;

const long long INF = 1e15;

int K,par[2005],par_w[2005],deg[2005],depth[2005],jump[2005],jumpdeg[2005],need[2005];
long long dp[2005][2005][2];
vector<pair<int,int>> adj[2005];

void dfs1(int v,int p,int p_w)
{
    par[v] = p;
    par_w[v] = p_w;
    depth[v] = depth[p] + 1;
    if(depth[jump[p]] - depth[jump[jump[p]]] == depth[p] - depth[jump[p]])
    {
        jump[v] = jump[jump[p]];
        jumpdeg[v] = max({need[p],jumpdeg[p],jumpdeg[jump[p]]});
    }
    else
    {
        jump[v] = p;
        jumpdeg[v] = need[p];
    }
    need[v] = deg[v];
    for(auto e : adj[v])
    {
        int u = e.first;
        int w = e.second;
        if(u != p)
        {
            dfs1(u,v,w);
            need[v] = max(need[v],deg[u]);
        }
    }
}

int find_nxt(int v,int k) //gives nxt nde whose par has weight >= k or root if it does not exist
{
    while(v != 1 && need[par[v]] < k)
    {
        if(jumpdeg[v] < k)
            v = jump[v];
        else
            v = par[v];
    }
    return v;
}

void dfs2(int v,int p)
{

    for(auto e : adj[v])
    {
        int u = e.first;
        int w = e.second;
        if(u != p)
            dfs2(u,v);
    }
    dp[v][0][1] = INF;
    for(int k = 0 ; k <= need[v] ; k++)
    {
        if(k)
            dp[v][k][1] = 0;
        dp[v][k][0] = par_w[v];
        vector<int> temp;
        for(auto e : adj[v])
        {
            int u = e.first;
            if(u != p)
            {
                if(dp[u][k][0]==0)
                    dp[u][k][0] = par_w[u];
                dp[v][k][0] += dp[u][k][0];
                dp[v][k][1] += dp[u][k][0];
                temp.push_back(dp[u][k][0] - dp[u][k][1]);
            }
        }
        sort(temp.begin(),temp.end(),greater<long long>());
        int L = temp.size();
        for(int i = 0 ; i < min(L,k-1) ; i++)
            if(temp[i] > 0)
            {
                dp[v][k][0] -= temp[i];
                dp[v][k][1] -= temp[i];
            }
        if(k > 0 && L >= k && temp[k-1] > 0)
            dp[v][k][0] -= temp[k-1];
        int nxt = find_nxt(v,k-1);
        if(nxt != v)
        {
            if(dp[nxt][k][0]==0)
                dp[nxt][k][0] = par_w[nxt];
            dp[nxt][k][0] += min(dp[v][k][0],dp[v][k][1]);
            dp[nxt][k][1] += min(dp[v][k][0],dp[v][k][1]);
        }
    }
}

std::vector<long long> minimum_closure_costs(int N, std::vector<int> U,std::vector<int> V, std::vector<int> W) 
{
    K = N;
    for(int i = 0 ; i < N-1 ; i++)
    {
        U[i]++;
        V[i]++;
        adj[U[i]].push_back({V[i],W[i]});
        adj[V[i]].push_back({U[i],W[i]});
        deg[U[i]]++;
        deg[V[i]]++;
    }
    dfs1(1,1,0);
    dfs2(1,1);
    vector<long long> ret;
    for(int k = 0 ; k < K ; k++)
        ret.push_back(dp[1][k][0]);
    return ret;
}
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