Submission #1147435

#	Time	Username	Problem	Language	Result	Execution time	Memory
1147435		aminjon__	Race (IOI11_race)	C++20	100 / 100	305 ms	85420 KiB

race

#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define endl '\n'
typedef unsigned int uint;
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
using namespace std;

#include "race.h"

int best_path(int N, int K, int H[][2], int L[])
{
    vector<vector<pair<ll, ll>>> rebr(N + 1);
    for (int i = 0; i < N - 1; i++)
    {
        rebr[H[i][0]].push_back({H[i][1], L[i]});
        rebr[H[i][1]].push_back({H[i][0], L[i]});
    }
    ll ans = LLONG_MAX;

    function<set<pair<ll, ll>>(ll, ll, ll, ll)> dfs;

    dfs =
        [&](ll x, ll p, ll sum, ll depth) {
            set<pair<ll, ll>> Suffix;
            Suffix.insert({sum, depth});
            for (auto g : rebr[x])
            {
                if (g.first == p)
                {
                    continue;
                }

                set<pair<ll, ll>> govno = dfs(g.first, x, sum + g.second, depth + 1);

                if (Suffix.size() < govno.size())
                {
                    swap(govno, Suffix);
                }
                for (auto g : govno)
                {
                    if (g.first == sum + K)
                    {
                        ans = min(g.second - depth, ans);
                        continue;
                    }
                    auto r = Suffix.upper_bound({sum + sum + K - g.first, 0});

                    if (r != Suffix.end() && (r->first) == sum + sum + K - g.first)
                    {
                        ans = min(ans, g.second + (r->second) - (depth * 2));
                    }
                }

                for (auto g : govno)
                {
                    Suffix.insert(g);
                }
                 auto r = Suffix.upper_bound({sum + K , 0});
                  if (r != Suffix.end() && (r->first) == sum + K)
                    {
                        ans = min(ans, (r->second) - depth);
                    }
            }
        

    return Suffix;
};

dfs(0, -1, 0, 1);

return (ans == LLONG_MAX ? -1 : ans);
}

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