Submission #252996

#	Time	Username	Problem	Language	Result	Execution time	Memory
252996		Kubin	Race (IOI11_race)	C++17	0 / 100	7 ms	384 KiB

race

#include <bits/stdc++.h>

using namespace std;

vector<vector<pair<size_t, int>>> graph;

const int oo = INT_MAX / 3;
int& rd(map<int, int>& m, int key)
{
    auto it = m.find(key);
    if(it == m.end()) it = m.emplace_hint(it, key, +oo);
    return it->second;
}
void mini(map<int, int>& m, int key, int value)
{
    rd(m, key) = min(rd(m, key), value);
}

void dfs_map_paths(size_t u, int s, int d, map<int, int>& m,
                   size_t glock = SIZE_MAX, size_t lock = SIZE_MAX)
{
    if(d > +oo) return;
    mini(m, s, d);
    for(auto [v, w] : graph[u])
        if(v != lock and v != glock)
            dfs_map_paths(v, s + w, d + 1, m, glock, u);
}


int best_path(int _n, int k, int H[][2], int L[])
{
    const size_t n = _n;

    graph.resize(n);
    for(size_t i = 0; i < n - 1; i++)
    {
        graph[H[i][0]].emplace_back(H[i][1], L[i]);
        graph[H[i][1]].emplace_back(H[i][0], L[i]);
    }

    int result = +oo;
    for(size_t f = 0; f < n; f++)
    {
        map<int, int> pre = {{0, 0}};
        for(auto [v, w] : graph[f])
        {
            map<int, int> cur;
            dfs_map_paths(v, w, 1, cur);

            for(auto [s, d] : cur)
                result = min(result, d + rd(pre, k - s));
            for(auto [s, d] : cur)
                mini(pre, s, d);
        }

    }

    return result >= +oo ? -1 : result;
}

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