Submission #957340

#	Time	Username	Problem	Language	Result	Execution time	Memory
957340		Haidara314	Race (IOI11_race)	C++17	0 / 100	2 ms	11100 KiB

race

#include "race.h"
#include <bits/stdc++.h>
#define ll long long
#define F first
#define S second
using namespace std;
int ans=1e9;
ll k;
vector<pair<int,ll>>adj[200005];
ll dep[200005];
int dis[200005];
map<ll,int> dfs(int u,int p)
{
    map<ll,int>y;

    for(auto x:adj[u])
    {
        if(x.F!=p)
        {
            dep[x.F]=dep[u]+x.S;
            dis[x.F]=dis[u]+1;
            map<ll,int>j=dfs(x.F,u);
            if(j.size()>=y.size())
                swap(j,y);
            for(auto f:j)
            {
                ll z=2;
                z*=dep[u];
                z+=k-f.F;
                if(y[z])
                {
                    ans=min(ans,y[z]+f.S-2*dis[u]);
                }
            }
            for(auto g:j)
            {
                if(y[g.F])
                y[g.F]=min(y[g.F],g.S);
                else
                    y[g.F]=g.S;
            }
        }
    }
    y[dep[u]]=dis[u];
    return y;
}
int best_path(int N, int K, int H[][2], int L[])
{
 k=K;
 for(int i=0;i<N-1;i++)
 {
     adj[H[i][0]].push_back({H[i][1],L[i]});
     adj[H[i][1]].push_back({H[i][0],L[i]});
 }
 dis[0]=1;
 dfs(0,-1);
  if(ans==1e9)
    ans=-1;
  return ans;
}

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