Submission #798135

#	Time	Username	Problem	Language	Result	Execution time	Memory
798135		TheSahib	Werewolf (IOI18_werewolf)	C++14	100 / 100	3902 ms	407320 KiB

werewolf

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

using namespace std;

const int MAX = 2e5 + 5;
const int BLOCK = 30;
const int LOGMAX = 18;

struct order{
    vector<int> v;
    bitset<MAX> st[MAX / BLOCK + 2];
    void preCalc(){
        int p = 0;
        for (int i = 0; i < v.size(); i++)
        {
            if(i % BLOCK == 0){
                p++;
                st[p] = st[p - 1];
            }
            st[p][v[i]] = 1;
        }
    }
    bitset<MAX> query(int p){
        bitset<MAX> ans = st[p / BLOCK];
        for (int i = p / BLOCK * BLOCK; i <= p; i++)
        {
            ans[v[i]] = 1;
        }
        return ans;
    }
};

int n;
struct graph{
    vector<int> tree[MAX];
    int par[LOGMAX][MAX];
    order v;
    int timeIn[MAX], timeOut[MAX];

    void dfs(int node, int p){
        par[0][node] = p;
        timeIn[node] = v.v.size();
        v.v.push_back(node);
        for(int to:tree[node]){
            if(to == p) continue;
            dfs(to, node);
        }
        timeOut[node] = v.v.size() - 1;
    }
    void preCalc(){
        for (int j = 1; j < LOGMAX; j++)
        {
            for (int i = 0; i < n; i++)
            {
                par[j][i] = par[j - 1][par[j - 1][i]];
            }
        }
        v.preCalc();
    }
    int lift1(int v, int a){
        for(int j = LOGMAX - 1; j >= 0; --j){
            int u = par[j][v];
            if(u >= a){
                v = u;
            }
        }
        return v;
    }
    int lift2(int v, int a){
        for(int j = LOGMAX - 1; j >= 0; --j){
            int u = par[j][v];
            if(u <= a){
                v = u;
            }
        }
        return v;
    }
    bitset<MAX> ask(int node){
        return v.query(timeOut[node]) ^ v.query(timeIn[node] - 1);
    }
};

vector<int> g[MAX];
graph tree1, tree2;

struct DSU{
    int par[MAX];
    bool b = 0;
    void init(int N, bool _b){
        b = _b;
        memset(par, -1, sizeof(par));
    }
    int get(int node){
        if(par[node] < 0) return node;
        return par[node] = get(par[node]);
    }
    bool unite(int v, int u){
        v = get(v);
        u = get(u);
        if(v == u) return false;
        if(v < u && b) swap(v, u);
        if(v > u && !b) swap(v, u);
        par[v] += par[u];
        par[u] = v;
        return true;
    }
};

vector<int> check_validity(int N, vector<int> X, vector<int> Y, vector<int> S, vector<int> E, vector<int> L, vector<int> R) {
    n = N;
    DSU dsu;
    for (int i = 0; i < X.size(); i++)
    {
        g[X[i]].push_back(Y[i]);
        g[Y[i]].push_back(X[i]);
    }
    dsu.init(N, 0);
    for (int node = N - 1; node >= 0; node--)
    {
        for(int to:g[node]){
            if(to < node) continue;
            int a = dsu.get(to);
            if(dsu.unite(node, to)){
                tree1.tree[node].push_back(a);
            }
        }
    }
    dsu.init(N, 1);
    for (int node = 0; node < N; node++)
    {
        for(int to:g[node]){
            if(to > node) continue;
            int a = dsu.get(to);
            if(dsu.unite(node, to)){
                tree2.tree[node].push_back(a);
            }
        }
    }
    tree1.dfs(0, 0);
    tree2.dfs(n - 1, n - 1);
    tree1.preCalc();
    tree2.preCalc();

    vector<int> ans(S.size());
    for (int i = 0; i < S.size(); i++)
    {
        int a = tree1.lift1(S[i], L[i]);
        int b = tree2.lift2(E[i], R[i]);
        ans[i] = (tree1.ask(a) & tree2.ask(b)).any();
    }
    return ans;
}

Compilation message (stderr)

werewolf.cpp: In member function 'void order::preCalc()':
werewolf.cpp:15:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |         for (int i = 0; i < v.size(); i++)
      |                         ~~^~~~~~~~~~
werewolf.cpp: In function 'std::vector<int> check_validity(int, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
werewolf.cpp:113:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |     for (int i = 0; i < X.size(); i++)
      |                     ~~^~~~~~~~~~
werewolf.cpp:146:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  146 |     for (int i = 0; i < S.size(); i++)
      |                     ~~^~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 8 / 8
• Subtask 3: 34 / 34
• Subtask 4: 51 / 51