Submission #1231136

#	Time	Username	Problem	Language	Result	Execution time	Memory
1231136		domi	Race (IOI11_race)	C++20	Compilation error	0 ms	0 KiB

race

#include <bits/stdc++.h>
#include "race.h"

#define int long long
#define fi first
#define se second

#define sz(a) (int)((a).size())
#define all(a) (a).begin(), (a).end()

#define lsb(x) (x & (-x))
#define vi vector<int>
#define YES { cout << "YES" << endl; return; }
#define NO { cout << "NO" << endl; return; }

using ll = long long;
using pii = std::pair<int, int>;

const int NMAX = 2e5;
const int KMAX = 1e6;

using namespace std;

vector<pii> T[NMAX + 5];
int sz[NMAX + 5], used[NMAX + 5], best[KMAX + 5], n, k, ans;

void prec_sz(int nod, int p = -1) {
    sz[nod] = 1;
    for (auto &[son, cost] : T[nod]) {
        if (son == p || used[son]) continue;
        prec_sz(son, nod);
        sz[nod] += sz[son];
    }
}

int get_centroid(int nod, int p, int total) {
    for (auto &[son, cost] : T[nod]) {
        if (son == p || used[son]) continue;
        if (sz[son] > total / 2)
            return get_centroid(son, nod, total);
    }
    return nod;
}

void update(int nod, int p, int sum, int depth) {
    if (sum > k) return;
    best[sum] = min(best[sum], depth);
    for (auto &[son, cost] : T[nod]) {
        if (son == p || used[son]) continue;
        update(son, nod, sum + cost, depth + 1);
    }
}

void remove(int nod, int p, int sum, int depth) {
    if (sum > k) return;
    best[sum] = LLONG_MAX;
    for (auto &[son, cost] : T[nod]) {
        if (son == p || used[son]) continue;
        remove(son, nod, sum + cost, depth + 1);
    }
}

void query(int nod, int p, int sum, int depth) {
    if (sum > k) return;
    if (best[k - sum] != LLONG_MAX)
        ans = min(ans, best[k - sum] + depth);
    for (auto &[son, cost] : T[nod]) {
        if (son == p || used[son]) continue;
        query(son, nod, sum + cost, depth + 1);
    }
}

void solve(int nod) {
    prec_sz(nod);
    int centroid = get_centroid(nod, -1, sz[nod]);
    used[centroid] = true;

    best[0] = 0;

    for (auto &[son, cost] : T[centroid]) {
        if (used[son]) continue;
        query(son, centroid, cost, 1);
        update(son, centroid, cost, 1);
    }

    for (auto &[son, cost] : T[centroid]) {
        if (used[son]) continue;
        remove(son, centroid, cost, 1);
    }

    for (auto &[son, cost] : T[centroid]) {
        if (!used[son])
            solve(son);
    }
}

int best_path(int N, int K, int H[][2], int L[]) {
    n = N, k = K;
    ans = LLONG_MAX;

    for (int i = 0; i < n; i++) {
        T[i].clear();
        used[i] = 0;
    }

    for (int i = 0; i <= k; i++) best[i] = LLONG_MAX;

    for (int i = 0; i < n - 1; i++) {
        int u = H[i][0], v = H[i][1], w = L[i];
        T[u].emplace_back(v, w);
        T[v].emplace_back(u, w);
    }

    solve(0);
    return (ans == LLONG_MAX ? -1 : ans);
}

// signed main() {
//     cin.tie(nullptr)->sync_with_stdio(false);
//
//     int N, K;
//     cin >> N >> K;
//
//     int H[NMAX][2];
//     int L[NMAX];
//
//     for (int i = 0; i < N - 1; i++) {
//         cin >> H[i][0] >> H[i][1] >> L[i];
//     }
//
//     int answer = best_path(N, K, H, L);
//     cout << answer << '\n';
//
//     return 0;
// }

Compilation message (stderr)

/usr/bin/ld: /tmp/ccCFGdYl.o: in function `main':
grader.cpp:(.text.startup+0x28): undefined reference to `best_path(int, int, int (*) [2], int*)'
collect2: error: ld returned 1 exit status