Submission #1264359

#	Time	Username	Problem	Language	Result	Execution time	Memory
1264359		BlockOG	경주 (Race) (IOI11_race)	C++20	21 / 100	3096 ms	32068 KiB

race

#include <bits/stdc++.h>

// mrrrow meeow :3
// go play vivid/stasis now! it's free on steam

#define fo(i, a, b) for (auto i = (a); i < (b); i++)
#define of(i, a, b) for (auto i = (b); i-- > (a);)
#define f first
#define s second
#define pb push_back
#define pob pop_back
#define lb lower_bound
#define ub upper_bound
#define be(a) a.begin(), a.end()
using namespace std;

int ____init = [] {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    return 0;
}();

vector<pair<int, int>> adj[200000];
int nd[200000];
long long nl[200000];
int k;

pair<unordered_map<long long, int>, int> dfs(int i, int p = -1, int d = 0, long long l = 0) {
    nd[i] = d, nl[i] = l;

    unordered_map<long long, int> m = {{l, d}};
    int md = 1000000;
    for (auto [j, jl] : adj[i]) {
        if (j == p) continue;
        auto [rm, rmd] = dfs(j, i, d + 1, l + jl);
        md = min(md, rmd);
        // for (auto it = rm.ub(l + k); it != rm.end(); rm.erase(it++));
        if (rm.size() > m.size()) swap(rm, m);
        for (auto [cl, cd] : rm) {
            if (m.count(l + k - (cl - l))) md = min(md, cd - d + m[l + k - (cl - l)] - d);
        }
        for (auto [cl, cd] : rm) {
            if (m.count(cl)) m[cl] = min(m[cl], cd);
            else m[cl] = cd;
        }
    }

    return {m, md};
}

int best_path(int n, int K, int h[][2], int l[]) {
    k = K;
    fo(i, 0, n - 1) {
        adj[h[i][0]].pb({h[i][1], l[i]});
        adj[h[i][1]].pb({h[i][0], l[i]});
    }

    int res = dfs(0).s;
    return res == 1000000 ? -1 : res;
}

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