Submission #587572

#	Time	Username	Problem	Language	Result	Execution time	Memory
587572		Bobonbush	Race (IOI11_race)	C++17	0 / 100	0 ms	340 KiB

race

#include <bits/stdc++.h>
#define foreach for
#define in :
using namespace std;
typedef long long ll;

/*
Konichiwa
Konichiwa
Ara ~~ ara

Bob no taisuki - Shinobu Kocho
    * * * * *
  *          *
 *         *
*         *        I love SHINOBU <3 <3 <3
 *         *
  *          *
    * * * * *
*/

/*
_________________________


    Author : Bob15324

_________________________
*/

template<class X , class Y>
    bool Minimize(X & x , Y y)
    {
        if( x == -1 || (x >y && y > 0))
        {
            x = y;
            return true;
        }
        return false;
    }

template<class X , class Y>
    bool Maximize(X & x , Y y)
    {
        if( x < y)
        {
            x = y;
            return true;
        }
        return false;
    }

/* End of templates. Let's see what do we have here */
const int N = 2e5+1;
int res = -1;
class GRAPH
{
    private:
        vector<set<pair<int ,int >>>vertices;
        vector<int>sub_size;
        vector<map<int ,int >>dict;
    public:
        GRAPH(int _n)
        {
            vertices.resize(_n+1);
            sub_size.resize(_n+1);
            dict.resize(_n+1);
        }

        void AddEdge(int u ,int v ,int w)
        {
            vertices[u].insert(make_pair(v , w));
            vertices[v].insert(make_pair(u , w));
        }

        int DFS(int u ,int daddy)
        {
            sub_size[u] = 1;
            foreach(pair<int ,int > adj in vertices[u])
            {
                int v = adj.first;
                if(v == daddy)
                {
                    continue;
                }
                sub_size[u] += DFS(v , u);
            }
            return  sub_size[u];
        }

        int centroid(int u ,int daddy , int lim)
        {
            foreach(pair<int ,int > adj in vertices[u])
            {
                int v = adj.first;
                if(v == daddy)
                {
                    continue;
                }
                if(sub_size[v] > lim)
                {
                    return centroid(v , u , lim);
                }
            }
            return u;
        }

        void dfs2(int u ,int daddy ,int base  , int distance , int s ,int k)
        {
            if(dict[base].count(s))
            {
                Minimize(dict[base][s], distance );
            }else
            {

                dict[base][s] = distance;
            }
            foreach(pair<int , int >adj in vertices[u])
            {
                int v = adj.first;
                if ( v== daddy)
                {
                    continue;
                }
                if(s + adj.second > k)
                {
                    continue;
                }
                dfs2(v , u , base , distance + 1 , s + adj.second  , k);
            }
        }

        void Build(int u, int daddy ,int k )
        {
            int lim = DFS(u , daddy);
            int _c = centroid(u , daddy , lim >> 1);

            dfs2(_c , daddy , _c , 0 , 0 , k);

            dict[_c][0] = 0;

            foreach(auto  val in dict[_c])
            {
                if(dict[_c].count(k - val.first))
                {
                    Minimize(res , dict[_c][k-val.first] + val.second);
                }
            }

            set<pair<int ,int >> temp = vertices[_c];

            foreach(pair<int ,int > adj in temp )
            {
                vertices[_c].erase(adj);
                vertices[adj.first].erase(make_pair(_c , adj.second));
                Build(adj.first , _c , k);
            }
        }
};


int best_path(int n , int m ,int H[][2] , int L[])
{
    GRAPH graph(n);
    for(int i = 0 ; i < n -1 ; i++)
    {
        H[i][0]++;
        H[i][1]++;
        graph.AddEdge(H[i][0] , H[i][1] , L[i]);
    }
    graph.Build(1 , - 1 , m);
    return res;
}


//Ehem. My code is amazing. Pay me 2$.Thank you.

• Subtask 1: 0 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57