Submission #556731

#	Time	Username	Problem	Language	Result	Execution time	Memory
556731		RaresFelix	Inside information (BOI21_servers)	C++17	50 / 100	378 ms	67992 KiB

servers

#include <bits/stdc++.h>
#define MN 120071
#define MK 20
using namespace std;
int n, k;
vector<pair<int, int> > L0[MN];
vector<int> L[MN];
vector<tuple<int, int, int, int> > Queries;
namespace BASIC {
    int Niv[MN], Val[MN], Par[MN], NiceUp[MN]; 
    int Maxi[MK][MN], Nice[2][MK][MN], Stramos[MK][MN];
    void init() {
        ///aleg rad arbitrar in 1
        function<void(int, int, int, int)> dfs0 = [&](int u, int p, int niv, int val) {
            Val[u] = val;
            Niv[u] = niv;
            Par[u] = p;
            for(auto &[it, w] : L0[u]) if(it != p) {
                dfs0(it, u, niv + 1, w);
            } 
            if(Niv[u] > 1) NiceUp[u] = Val[u] < Val[p];
        };
        dfs0(1, 0, 0, 0);
        for(int i = 1; i <= n; ++i) Stramos[0][i] = Par[i];
        for(int k = 1; k < MK; ++k) {
            for(int i = 1; i <= n; ++i)
                Stramos[k][i] = Stramos[k-1][Stramos[k-1][i]];
        }
        for(int i = 1; i <= n; ++i)
            Nice[0][0][i] = NiceUp[i] ^ 1, Nice[1][0][i] = NiceUp[i];
        for(int d = 0; d < 2; ++d) {
            for(int k = 1; k < MK; ++k) {
                for(int i = 1; i <= n; ++i) {
                    Nice[d][k][i] = Nice[d][k-1][i] & Nice[d][k-1][Stramos[k-1][i]];
                }
            }
        }
        for(int i = 1; i <= n; ++i)
            Maxi[0][i] = Val[i];
        for(int k = 1; k < MK; ++k)
            for(int i = 1; i <= n; ++i)
                Maxi[k][i] = max(Maxi[k-1][i], Maxi[k-1][Stramos[k-1][i]]);
    }
    bool is_okay(int u, int v) { ///!!! ORDER IS VERY IMPORTANT U => V
        bool rez = 1;
        if(Niv[u] > Niv[v]) {
            for(int k = MK - 1; k >= 0; --k) {
                if((Niv[u] - Niv[v] - 1) & (1 << k)) {
                    rez &= Nice[1][k][u];
                    u = Stramos[k][u];
                }
            }
            if(Par[u] != v) rez &= Nice[1][0][u]; 
            u = Par[u];
        } else if (Niv[u] < Niv[v]) {
            for(int k = MK - 1; k >= 0; --k) {
                if((Niv[v] - Niv[u] - 1) & (1 << k)) {
                    rez &= Nice[0][k][v];
                   // printf("debug %d %d %d -- ", k, v, rez);
                    //printf("debug %d %d %d\n", Nice[0][0][v], Nice[0][1][v], Stramos[1][v]);
                    
                    v = Stramos[k][v];
                }
            }
            if(Par[v] != u) rez &= Nice[0][0][v];
            v = Par[v];
        }
        ///acum sunt la acelasi nivel
        assert(Niv[u] == Niv[v]);
        if(v == u || !rez) return rez;
        for(int k = MK - 1; k >= 0; --k) {
            if(Stramos[k][u] != Stramos[k][v]) {
                rez &= Nice[0][k][v];
                rez &= Nice[1][k][u];
                v = Stramos[k][v];
                u = Stramos[k][u];
            }
        }
        if(u != v) rez &= Val[u] < Val[v];
        return rez;
    }
    int max_on_path(int u, int v) {
        int rez = 0;
        if(Niv[u] < Niv[v]) swap(u, v);
        if(Niv[u] != Niv[v])
            for(int k = MK - 1; k >= 0; --k)
                if((Niv[u] - Niv[v] - 1) & (1 << k)) {
                    rez = max(rez, Maxi[k][u]);
                    u = Stramos[k][u];
                }
        if(Niv[u] != Niv[v]) {
            rez = max(rez, Maxi[0][u]);
            u = Par[u];
        }
        assert(Niv[u] == Niv[v]);
        for(int k = MK - 1; k >= 0; --k)
            if(Stramos[k][u] != Stramos[k][v]) {
                rez = max(rez, Maxi[k][u]);
                rez = max(rez, Maxi[k][v]);
                u = Stramos[k][u];
                v = Stramos[k][v];
            }
        if(u != v) rez = max({rez, Val[u], Val[v]});
        return rez;

    }
}

int main() {
    //cin.tie(0)->sync_with_stdio(0);
    cin >> n >> k;
    for(int i = 1, a, b; i <= n + k - 1; ++i) {
        char tip;
        cin >> tip;
        if(tip == 'S') {
            cin >> a >> b;
            L0[a].push_back({b, i});
            L0[b].push_back({a, i});
        } else if(tip == 'Q') {
            cin >> a >> b;
            Queries.push_back({0, a, b, i});
        } else {
            cin >> a;
            Queries.push_back({1, a, 0, i});
        }
    }
    BASIC::init();
    for(auto &[tip, a, b, id] : Queries) {
        if(tip == 0) {
            int ok = BASIC::is_okay(b, a);
            ok &= BASIC::max_on_path(b, a) < id;
            cout << (ok ? "yes\n" : "no\n");
        }
    }
    return 0;
}

• Subtask 1: 2.5 / 2.5
• Subtask 2: 0 / 2.5
• Subtask 3: 2.5 / 2.5
• Subtask 4: 0 / 2.5
• Subtask 5: 5 / 5
• Subtask 6: 0 / 5
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 12.5 / 12.5
• Subtask 10: 0 / 12.5
• Subtask 11: 17.5 / 17.5
• Subtask 12: 0 / 17.5