Submission #962156

#	Time	Username	Problem	Language	Result	Execution time	Memory
962156		simona1230	Dreaming (IOI13_dreaming)	C++17	0 / 100	42 ms	16364 KiB

dreaming

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

using namespace std;
int n,m,k;
vector<pair<int,int> > v[100001];
int c[100001],num;
int in;
int r[100001];
int lp[1000001];
int furt[100001],ver[100001];
int sfurt[100001];
int act[100001];

void prec(int i,int p)
{
    c[i]=num;
    for(int j=0; j<v[i].size(); j++)
    {
        int nb=v[i][j].first;
        if(nb!=p)
        {
            lp[nb]=v[i][j].second;
            prec(nb,i);
        }
    }
}

int up[100001];
int minn[100001];
int dfs(int i,int p)
{
    if(v[i].size()==1&&p||v[i].size()==0)return 0;
    int curr=0,f1=0,f2=0;
    for(int j=0; j<v[i].size(); j++)
    {
        int nb=v[i][j].first;
        if(nb==p)continue;
        int f=dfs(nb,i)+v[i][j].second;
        if(furt[i]<f)
        {
            sfurt[i]=furt[i];
            furt[i]=f;
            ver[i]=nb;
        }
        else sfurt[i]=max(sfurt[i],f);
        curr=max(curr,f);
        if(f>=f1)
        {
            f2=f1;
            f1=f;
        }
        else if(f>=f2)
        {
            f2=f;
        }
    }

    in=max(in,f1+f2);
    //cout<<i-1<<": "<<furt[i]<<" "<<ver[i]<<" "<<sfurt[i]<<endl;

    //cout<<i<<" - "<<curr<<endl;
    return curr;
}

void up_(int i,int p)
{
    for(int j=0;j<v[i].size();j++)
    {
        int nb=v[i][j].first;
        if(nb==p)continue;
        int add=furt[i];
        if(ver[i]==nb)add=sfurt[i];
        up[nb]=lp[nb]+max(up[i],add);
        up_(nb,i);
        //cout<<nb-1<<" // "<<up[nb]<<endl;
    }
}

int solve()
{
    for(int i=1; i<=num; i++)
    {
        minn[i]=1e9;
        //cout<<"** "<<r[i]-1<<endl;
        dfs(r[i],0);
        up_(r[i],0);
    }

    for(int i=1; i<=n; i++)
    {
        //cout<<c[i]<<" "<<i<<" "<<dfs(i,0)<<endl;
        minn[c[i]]=min(minn[c[i]],max(furt[i],up[i]));
    }

    in=max(in,minn[num-1]+minn[num-2]+2*k);

    sort(minn+1,minn+num+1);
    return max(k+minn[num]+minn[num-1],in);
}

int travelTime(int N,int M,int L,int A[],int B[],int T[])
{
    n=N;
    m=M;
    k=L;
    //cout<<n<<" "<<m<<" "<<k<<endl;

    for(int i=0;i<m;i++)
    {
        A[i]++;
        B[i]++;
        //cout<<A[i]<<" "<<B[i]<<" "<<T[i]<<endl;
        v[A[i]].push_back({B[i],T[i]});
        v[B[i]].push_back({A[i],T[i]});
    }

    for(int i=1; i<=n; i++)
        if(!c[i])
        {
            num++;
            r[num]=i;
            prec(i,0);
        }
    return solve();
}


/*
12 8 2
0 8 4
8 2 2
2 7 4
5 11 3
5 1 7
1 3 1
1 9 5
10 6 3
*/

Compilation message (stderr)

dreaming.cpp: In function 'void prec(int, int)':
dreaming.cpp:18:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |     for(int j=0; j<v[i].size(); j++)
      |                  ~^~~~~~~~~~~~
dreaming.cpp: In function 'int dfs(int, int)':
dreaming.cpp:33:22: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   33 |     if(v[i].size()==1&&p||v[i].size()==0)return 0;
      |        ~~~~~~~~~~~~~~^~~
dreaming.cpp:35:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |     for(int j=0; j<v[i].size(); j++)
      |                  ~^~~~~~~~~~~~
dreaming.cpp: In function 'void up_(int, int)':
dreaming.cpp:68:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |     for(int j=0;j<v[i].size();j++)
      |                 ~^~~~~~~~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 10
• Subtask 3: 0 / 23
• Subtask 4: 0 / 18
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23