Submission #734276

#	Time	Username	Problem	Language	Result	Execution time	Memory
734276		bin9638	Road Closures (APIO21_roads)	C++17	24 / 100	2080 ms	16436 KiB

roads

#include <bits/stdc++.h>

#ifndef SKY
#include "roads.h"
#endif // SKY

using namespace std;

#define N 100010
#define ll long long
#define fs first
#define sc second
#define ii pair<ll,int>
#define pb push_back

int k,n;
vector<ii>g[N];
ll cost[N],dp[N][2];

void build(int u,int p)
{
    for(auto v:g[u])
        if(v.sc!=p)
        {
            build(v.sc,u);
            cost[v.sc]=v.fs;
        }
}

ll solve(int u,int p,int sl)
{

    if(sl<0)
        return 2e14;
    ll res=0;
    // cout<<u<<" "<<p<<" "<<sl<<endl;
    vector<ll>s;
    for(auto v:g[u])
        if(v.sc!=p)
            if(dp[v.sc][0]<=dp[v.sc][1])
            {
                res+=dp[v.sc][0];
            }else
            {
                res+=dp[v.sc][1];
                s.pb(dp[v.sc][0]-dp[v.sc][1]);
            }
    //cout<<u<<" "<<p<<" "<<sl<<" "<<s.size()<<endl;
    sort(s.begin(),s.end());
    for(int i=0;i<(int)s.size()-sl;i++)
        res+=s[i];
    return res;
}

void DFS(int u,int p)
{
   // cout<<u<<" "<<k<<endl;
    for(auto v:g[u])
        if(v.sc!=p)
            DFS(v.sc,u);
    //0
    dp[u][0]=solve(u,p,k)+cost[u];
    //1
    dp[u][1]=solve(u,p,k-(u!=0));
}

vector<long long> minimum_closure_costs(int NNN, vector<int> UUU, vector<int> VVV, vector<int> WWW)
{
    n=NNN;
    for(int i=0;i<n-1;i++)
    {
        int u=UUU[i],v=VVV[i],w=WWW[i];
        g[u].pb({w,v});
        g[v].pb({w,u});
    }
    cost[0]=1e18;
    build(0,-1);
    vector<ll>kq;
    for(k=0;k<n;k++)
    {
        memset(dp,0x3f3f,sizeof(dp));
        DFS(0,-1);
        kq.pb(dp[0][1]);
    }
    return kq;
}

#ifdef SKY
int main()
{
    freopen("A.inp","r",stdin);
    freopen("A.out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    int n;
    cin>>n;
    vector<int>U(n-1),V(n-1),W(n-1);
    for(int i=0;i<n-1;i++)
        cin>>U[i]>>V[i]>>W[i];
    vector<ll>kq=minimum_closure_costs(n,U,V,W);
    for(auto u:kq)cout<<u<<" ";
    return 0;
}
#endif

Compilation message (stderr)

roads.cpp: In function 'long long int solve(int, int, int)':
roads.cpp:39:11: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else]
   39 |         if(v.sc!=p)
      |           ^

• Subtask 1: 0 / 5
• Subtask 2: 0 / 7
• Subtask 3: 14 / 14
• Subtask 4: 10 / 10
• Subtask 5: 0 / 17
• Subtask 6: 0 / 25
• Subtask 7: 0 / 22