Submission #840563

#	Time	Username	Problem	Language	Result	Execution time	Memory
840563		Mularstyle	Dreaming (IOI13_dreaming)	C++14	100 / 100	68 ms	18056 KiB

dreaming

#include "dreaming.h"
#include<bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define f first
#define s second
#define pb push_back
vector<pii> V[100008];
vector<int> grp[100008];
bool vis1[100008];
bool vis2[100008];
int mxdis[100008];
void ddfs(int prev,int cur,int dis)
{
    mxdis[cur]=max(mxdis[cur],dis);
    for(auto [w,v]:V[cur])
    {
        if(v!=prev)
        {
             ddfs(cur,v,dis+w);
        }
    }
}
void gdfs(int prev,int cur,int g)
{
    vis1[cur]=true;
    grp[g].pb(cur);
    for(auto [w,v]:V[cur])
    {
        if(v!=prev)
        gdfs(cur,v,g);
    }
}

int travelTime(int N, int M, int L, int A[], int B[], int T[]) {

    int u,v,w;
    for(int i=0;i<M;i++)
    {
        u=A[i];
        v=B[i];
        w=T[i];
        V[u].pb({w,v});
        V[v].pb({w,u});
    }
    for(int i=0;i<N;i++)
    {
        if(vis1[i])continue;
        gdfs(-1,i,i);
    }
    int mx1=-8,mx2=-8,mx3=-8,ans=0;
    for(int i=0;i<N;i++)
    {
        if(grp[i].empty())continue;
        int prev=N;
        for(int k=0;k<4;k++)
        {
            int cur=N;
            for(auto v:grp[i])
            {
                if(!vis2[v]&&mxdis[v]>=mxdis[prev]&&mxdis[v]>=mxdis[cur])
                    cur=v;
            }
            if(cur==N)/// <3
                break;
            ddfs(N,cur,0);
            vis2[cur]=true;
            prev=cur;
        }
        int mn=INT_MAX;//shortest from longest
        for(auto v:grp[i])
        {
            mn=min(mxdis[v],mn);
            ans=max(ans,mxdis[v]);
        }
        if(mn>=mx1)
            mx3=mx2,mx2=mx1,mx1=mn;
        else if(mn>=mx2)
            mx3=mx2,mx2=mn;
        else if(mn>=mx3)
            mx3=mn;
    }
    if(mx2!=-8)
        ans=max(ans,mx2+mx1+L);
    if(mx3!=-8)
        ans=max(ans,mx3+mx2+L+L);
    return ans;
}

Compilation message (stderr)

dreaming.cpp: In function 'void ddfs(int, int, int)':
dreaming.cpp:16:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   16 |     for(auto [w,v]:V[cur])
      |              ^
dreaming.cpp: In function 'void gdfs(int, int, int)':
dreaming.cpp:28:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   28 |     for(auto [w,v]:V[cur])
      |              ^

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