Submission #849416

#	Time	Username	Problem	Language	Result	Execution time	Memory
849416		Mr_Ph	Race (IOI11_race)	C++14	0 / 100	11 ms	84056 KiB

race

#include "race.h"
//#include "grader.cpp"
#include<bits/stdc++.h>
using namespace std;
vector<int>vs;
vector<int>vs1;
vector<vector<pair<int,int>>>adj;
int ans=1e9;
int pog=0;
int dp[200002][102];
void dfs(int node,int lol,int sum)
{
    vs[node]=true;
    if(sum>pog)
        return;
    if(sum==pog)
    {
        ans=min(ans,lol);
        return;
    }
    for(auto i:adj[node])
    {
        if(!vs[i.first])
        {
           // cout<<node<<" "<<i.first<<" "<<i.second<<endl;
            dfs(i.first,lol+1,sum+i.second);
        }
    }
}
int dfs1(int node,int sum,int p)
{
    if(sum>pog)
        return 1e9;
    if(sum==pog)
        return 0;
    if(dp[node][sum]!=-1)
        return dp[node][sum];
    int e=1e9;
    for(auto i:adj[node])
    {
        if(i.first==p)
            continue;
        e=min(e,dfs1(i.first,sum+i.second,node)+1);
    }
    return dp[node][sum]=e;
}
int best_path(int n, int k, int h[][2], int l[])
{
    memset(dp,-1,sizeof dp);
    pog=k;
    adj.resize(n+1);
    vs.resize(n+1);
    vs1=vs;
    for(int i=0; i<n-1; i++)
    {
       // cout<<h[i][0]<<" "<<h[i][1]<<" "<<l[i]<<endl;
        adj[h[i][0]].push_back({h[i][1],l[i]});
        adj[h[i][1]].push_back({h[i][0],l[i]});
    }
    if(n<=200000&&k<=100)
    {
        for(int i=0;i<n;i++)
            ans=min(ans,dfs1(i,0,-1));
    }
    else
    {
        for(int i=0; i<n; i++)
        {
            vs=vs1;
            dfs(i,0,0);
           // cout<<ans<<endl;
        }
    }
    if(ans>=1e9)
        ans=-1;
    return ans;
}

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