Submission #1090516

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090516		vivkostov	Race (IOI11_race)	C++14	0 / 100	2 ms	4956 KiB

race

#include <bits/stdc++.h>
#include "race.h"
using namespace std;
void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}
struct cell
{
    int a,b,c;
    void read()
    {
        cin>>a>>b>>c;
    }
};
int n,k,used[200005],dp[200005];
cell a[200005];
vector<cell>v[200005];
map<int,int>m,ne;
int otg;
void make_dp(int beg)
{
    int w;
    used[beg]=1;
    dp[beg]=1;
    for(int i=0;i<v[beg].size();i++)
    {
        w=v[beg][i].b;
        if(!used[w])
        {
            make_dp(w);
            dp[beg]+=dp[w];
        }
    }
}
void cl(int beg,int par)
{
    int w;
    used[beg]=0;
    for(int i=0;i<v[beg].size();i++)
    {
        w=v[beg][i].b;
        if(w!=par&&used[w]!=2)cl(w,beg);
    }
}
void dfs(int beg,int st,int lead,int br)
{
    used[beg]=1;
    cell w;
    if(!ne[st])
    {
        ne[st]=br;
    }
    else ne[st]=min(ne[st],br);
    for(int i=0;i<v[beg].size();i++)
    {
        w=v[beg][i];
        if(!used[w.b])
        {
            dfs(w.b,st+w.c,lead,br+1);
        }
        if(beg==lead)
        {
            for(auto j=ne.begin();j!=ne.end();j++)
            {
                int h=j->first;
                if(m[k-h])otg=min(otg,m[k-h]+j->second);
                if(m[h])m[h]=min(m[h],ne[h]);
                else m[h]=ne[h];
            }
            ne.clear();
        }
    }
}
void find_centroid(int beg,int par,int br)
{
    int w,l=0;
    used[beg]=1;
    for(int i=0;i<v[beg].size();i++)
    {
        w=v[beg][i].b;
        if(!used[w]&&dp[w]>=(br+1)/2)
        {
            find_centroid(w,beg,br);
            l=1;
        }
    }
    if(!l)
    {
        cl(beg,beg);
        m[0]=0;
        dfs(beg,0,beg,0);
        m.clear();
        cl(beg,beg);
        used[beg]=2;
        for(int i=0;i<v[beg].size();i++)
        {
            w=v[beg][i].b;
            if(!used[w])
            {
                make_dp(w);
                cl(w,w);
                find_centroid(w,w,dp[w]);
            }
        }
    }
}
int best_path(int N,int K,int H[][2],int L[])
//void read()
{
    //cin>>n>>k;
    n=N;
    k=K;
    for(int i=1;i<n;i++)
    {
        //cin>>a[i].a>>a[i].b;
        a[i].a=H[i][0];
        a[i].b=H[i][1];
    }
    for(int i=1;i<n;i++)
    {
        //cin>>a[i].c;
        a[i].c=L[i];
        v[a[i].a].push_back(a[i]);
        swap(a[i].a,a[i].b);
        v[a[i].a].push_back(a[i]);
    }
    otg=1000000000;
    dfs(0,0,0,0);
    make_dp(0);
    cl(0,0);
    find_centroid(0,0,dp[0]);
    cout<<otg<<endl;
    if(otg==1000000000)
    {
        //cout<<-1<<endl;
        return -1;
    }
    return otg;
}
/*int main()
{
    speed();
    read();
    return  0;
}
*/

Compilation message (stderr)

race.cpp: In function 'void make_dp(int)':
race.cpp:28:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<cell>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |     for(int i=0;i<v[beg].size();i++)
      |                 ~^~~~~~~~~~~~~~
race.cpp: In function 'void cl(int, int)':
race.cpp:42:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<cell>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |     for(int i=0;i<v[beg].size();i++)
      |                 ~^~~~~~~~~~~~~~
race.cpp: In function 'void dfs(int, int, int, int)':
race.cpp:57:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<cell>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |     for(int i=0;i<v[beg].size();i++)
      |                 ~^~~~~~~~~~~~~~
race.cpp: In function 'void find_centroid(int, int, int)':
race.cpp:81:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<cell>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |     for(int i=0;i<v[beg].size();i++)
      |                 ~^~~~~~~~~~~~~~
race.cpp:98:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<cell>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |         for(int i=0;i<v[beg].size();i++)
      |                     ~^~~~~~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57