Submission #625037

#	Time	Username	Problem	Language	Result	Execution time	Memory
625037		Hanksburger	Dreaming (IOI13_dreaming)	C++17	100 / 100	104 ms	14604 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;
vector<pair<long long, long long> > adj[100005];
priority_queue<pair<long long, long long> > pq;
long long dist[100005], par[100005];
vector<long long> vec, tor, z;
bool visited[100005];
int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
    for (long long i=0; i<M; i++)
    {
        adj[A[i]].push_back({B[i], T[i]});
        adj[B[i]].push_back({A[i], T[i]});
    }
    for (long long i=0; i<N; i++)
        dist[i]=1e18;
    long long mx=0;
    for (long long i=0; i<N; i++)
    {
        if (visited[i])
            continue;
        long long x, y, cur, len=1e18;
        dist[i]=0;
        pq.push({0, i});
        while (!pq.empty())
        {
            long long d=pq.top().first, u=pq.top().second;
            pq.pop();
            if (dist[u]!=-d)
                continue;
            vec.push_back(u);
            visited[u]=1;
            for (long long j=0; j<adj[u].size(); j++)
            {
                long long v=adj[u][j].first, w=adj[u][j].second;
                if (dist[u]+w<dist[v])
                {
                    dist[v]=dist[u]+w;
                    pq.push({-dist[v], v});
                }
            }
        }
//        cout << "vec: ";
//        for (long long u:vec)
//            cout << u << ' ';
//        cout << '\n';
        x=vec[0];
        for (long long j=1; j<vec.size(); j++)
            if (dist[x]<dist[vec[j]])
                x=vec[j];
        for (long long j=0; j<vec.size(); j++)
            dist[vec[j]]=1e18;
//        cout << "x=" << x << '\n';
        dist[x]=0;
        pq.push({0, x});
        while (!pq.empty())
        {
            long long d=pq.top().first, u=pq.top().second;
            pq.pop();
            if (dist[u]!=-d)
                continue;
            for (long long j=0; j<adj[u].size(); j++)
            {
                long long v=adj[u][j].first, w=adj[u][j].second;
                if (dist[u]+w<dist[v])
                {
                    par[v]=u;
                    dist[v]=dist[u]+w;
                    pq.push({-dist[v], v});
                }
            }
        }
        y=vec[0];
        for (long long j=1; j<vec.size(); j++)
            if (dist[y]<dist[vec[j]])
                y=vec[j];
//        cout << "y=" << y << '\n';
        cur=y;
        while (cur!=x)
        {
            tor.push_back(cur);
            cur=par[cur];
        }
        tor.push_back(x);
        for (long long u:tor)
            len=min(len, max(dist[u], dist[y]-dist[u]));
        mx=max(mx, dist[y]);
        z.push_back(len);
        vec.clear();
        tor.clear();
    }
    sort(z.begin(), z.end(), greater<long long>());
    if (z.size()==1)
        return mx;
    else if (z.size()==2)
        return max(mx, z[0]+z[1]+L);
    else
        return max(mx, max(z[0]+z[1]+L, z[1]+z[2]+L*2));
}

Compilation message (stderr)

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:34:34: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |             for (long long j=0; j<adj[u].size(); j++)
      |                                 ~^~~~~~~~~~~~~~
dreaming.cpp:49:30: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |         for (long long j=1; j<vec.size(); j++)
      |                             ~^~~~~~~~~~~
dreaming.cpp:52:30: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |         for (long long j=0; j<vec.size(); j++)
      |                             ~^~~~~~~~~~~
dreaming.cpp:63:34: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |             for (long long j=0; j<adj[u].size(); j++)
      |                                 ~^~~~~~~~~~~~~~
dreaming.cpp:75:30: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |         for (long long j=1; j<vec.size(); j++)
      |                             ~^~~~~~~~~~~

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