Submission #652383

#	Time	Username	Problem	Language	Result	Execution time	Memory
652383		dooompy	File Paths (BOI15_fil)	C++17	100 / 100	146 ms	5596 KiB

fil

#include "bits/stdc++.h"

using namespace std;

void abc() {cout << endl;}
template <typename T, typename ...U> void abc(T a, U ...b) {
    cout << a << ' ', abc(b...);
}
template <typename T> void printv(T l, T r) {
    while (l != r) cout << *l << " \n"[++l == r];
}
template <typename A, typename B> istream& operator >> (istream& o, pair<A, B> &a) {
    return o >> a.first >> a.second;
}
template <typename A, typename B> ostream& operator << (ostream& o, pair<A, B> a) {
    return o << '(' << a.first << ", " << a.second << ')';
}
template <typename T> ostream& operator << (ostream& o, vector<T> a) {
    bool is = false;
    for (T i : a) {o << (is ? ' ' : '{'), is = true, o << i;}
    return o << '}';
}

#ifdef local
#define test(args...) abc("[" + string(#args) + "]", args)
#else
#define test(args...) void(0)
#endif

using ll = long long;

bool possible[1000005];
int len[6005];
vector<int> adj[6005];
bool leaf[6005];
int cycle[1000005];

int ans[6005];

vector<int> active;

int n, k, m, s;

void updcycle(int root, int node, int state) {
    if (leaf[node]) return;

    int cycledist = len[node] - len[root] + s;

    if (cycledist > k) return;

    cycle[cycledist] += state;
    for (auto nxt : adj[node]) updcycle(root, nxt, state);
}

void dfs(int node) {
    if (leaf[node]) {
        // terminate
        int req = k - len[node];

        if (req == 0) {
            ans[node - n] = 1;
            return;
        }

        for (int i = 1; i * i <= req; i++) {
            if (req % i == 0) {
                if (cycle[i] || cycle[req / i]) {
                    ans[node - n] = 1;
                    return;
                }
            }
        }

        req -= s;

        // bridge

        for (int i = active.size() - 1; i >= 0; i--) {
            // bridge ending at i

            int dist = k - (len[node] - len[active[i]] + s);

            if (dist < 0) continue;
            if (possible[dist]) {
                ans[node - n] = 1;
                return;
            }
        }


        return;
    }

    // update cycles from this directory
    updcycle(node, node, 1);
    active.push_back(node);
    for (auto nxt : adj[node]) dfs(nxt);
    active.pop_back();
    updcycle(node, node, -1);
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
//    freopen("", "r", stdin);
//    freopen("", "w", stdout);
    cin >> n >> m >> k >> s;
    s++;

    possible[0] = true;

    for (int i = 1; i <= n; i++) {
        // folder
        int p, l; cin >> p >> l;
        l++;
        adj[p].push_back(i);
        len[i] = len[p] + l;

        possible[len[i]] = true;
    }

    for (int i = n + 1; i <= n + m; i++) {
        int p, l; cin >> p >> l;
        leaf[i] = true;
        l++;
        len[i] = len[p] + l;
        adj[p].push_back(i);
    }

    dfs(0);

    for (int i = 1; i <= m; i++) {
        if (ans[i]) {
            cout << "YES" << "\n";
        } else cout << "NO\n";
    }
}

• Subtask 1: 33 / 33
• Subtask 2: 33 / 33
• Subtask 3: 34 / 34