Submission #1035415

#	Time	Username	Problem	Language	Result	Execution time	Memory
1035415		andrei_iorgulescu	Dreaming (IOI13_dreaming)	C++14	100 / 100	63 ms	16896 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>

using namespace std;

bool viz[100005];
vector<pair<int,int>> g[100005];
int t[100005];
int dist[100005];

vector<int> cc;

void dfs(int nod)
{
    cc.push_back(nod);
    viz[nod] = true;
    for (auto vecin : g[nod])
    {
        if (!viz[vecin.first])
        {
            t[vecin.first] = nod;
            dist[vecin.first] = dist[nod] + vecin.second;
            dfs(vecin.first);
        }
    }
}

int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
    for (int i = 0; i < M; i++)
    {
        g[A[i]].push_back({B[i],T[i]});
        g[B[i]].push_back({A[i],T[i]});
    }
    vector<int> w;
    int maxd = 0;
    for (int i = 0; i < N; i++)
    {
        if (!viz[i])
        {
            cc.clear();
            dfs(i);
            int mx = 0,cn = i;
            for (auto it : cc)
            {
                if (dist[it] > mx)
                    mx = dist[it],cn = it;
            }
            for (auto it : cc)
                dist[it] = 0,viz[it] = false,t[it] = 0;
            cc.clear();
            dfs(cn);
            int rt = cn;
            mx = 0,cn = rt;
            for (auto it : cc)
            {
                if (dist[it] > mx)
                    mx = dist[it],cn = it;
            }
            vector<int> diam;
            while (cn != rt)
                diam.push_back(cn),cn = t[cn];
            diam.push_back(cn);
            maxd = max(maxd,mx);
            int ans = 1e9;
            for (auto it : diam)
                ans = min(ans,max(dist[it],mx - dist[it]));
            w.push_back(ans);
        }
    }
    if (w.size() == 1)
        return maxd;
    else
    {
        sort(w.begin(),w.end());
        int ans = w[w.size() - 1] + w[w.size() - 2] + L;
        if (w.size() >= 3)
            ans = max(ans,w[w.size() - 2] + w[w.size() - 3] + L + L);
        ans = max(ans,maxd);
        return ans;
    }
}

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