Submission #308053

#	Time	Username	Problem	Language	Result	Execution time	Memory
308053		daniel920712	Dreaming (IOI13_dreaming)	C++14	100 / 100	117 ms	13308 KiB

dreaming

#include "dreaming.h"
#include <vector>
#include <stdio.h>
using namespace std;
vector < pair < int , int > > Next[100005];
bool have[100005]={0};
int a=0,b=0,c=0,t=0,big=0,bb=0,where;
void F(int here,int con)
{
    if(con>=big)
    {
        big=con;
        where=here;
    }
    have[here]=1;
    for(auto i:Next[here]) if(!have[i.first]) F(i.first,con+i.second);
}
bool F2(int here,int Father,int con)
{
    if(con==big)
    {
        t=min(t,max(con,big-con));
        return 1;

    }

    for(auto i:Next[here])
    {
        if(i.first!=Father)
        {
            if(F2(i.first,here,con+i.second))
            {
                t=min(t,max(con,big-con));
                return 1;
            }
        }
    }
    return 0;
}
void F3(int here,int Father,int con)
{
    big=max(big,con);
    for(auto i:Next[here]) if(i.first!=Father) F3(i.first,here,con+i.second);
}
int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
    int i,how=0;
    for(i=0;i<M;i++)
    {
        Next[A[i]].push_back(make_pair(B[i],T[i]));
        Next[B[i]].push_back(make_pair(A[i],T[i]));
    }
    for(i=0;i<N;i++)
    {
        if(!have[i])
        {
            how++;
            big=0;
            where=0;
            F(i,0);
            F3(where,-1,0);
            //printf("%d\n",big);
            bb=max(bb,big);
            t=1e9;
            F2(where,-1,0);
            if(t>=a)
            {
                c=b;
                b=a;
                a=t;
            }
            else if(t>=b)
            {
                c=b;
                b=t;
            }
            else if(t>=c) c=t;
        }
    }
    //printf("%d %d %d %d\n",how,a,b,bb);
    if(how>=2) bb=max(bb,a+b+L);
    if(how>=3) bb=max(bb,b+c+2*L);

    return bb;
}

• Subtask 1: 14 / 14
• Subtask 2: 10 / 10
• Subtask 3: 23 / 23
• Subtask 4: 18 / 18
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23