Submission #1020200

#	Time	Username	Problem	Language	Result	Execution time	Memory
1020200		Issa	Werewolf (IOI18_werewolf)	C++17	49 / 100	272 ms	78420 KiB

werewolf

#include <bits/stdc++.h>
using namespace std;

const int maxn = 3e3 + 100;

int n;
int pref[maxn][maxn];
int suf[maxn][maxn];
vector<int> g[200100];

int get(int v, int p[]){
    if(p[v] == v) return v;
    return p[v] = get(p[v], p);
}

void join(int a, int b, int p[]){
    p[get(a, p)] = get(b, p);
}

void add(vector<int> &v){
    for(int &x: v) x++;
}

int mx[22][200100];
int mn[22][200100];
int b[200100], t;
int lg[200100];

void dfs(int v, int p = 0){
    t++; b[v] = t;
    mx[0][t] = mn[0][t] = v;
    for(int to: g[v]){
        if(to == p) continue;
        dfs(to, v);
    }
}

int getmn(int l, int r){
    int k = lg[r - l + 1];
    return min(mn[k][l], mn[k][r-(1<<k)+1]);
}

int getmx(int l, int r){
    int k = lg[r - l + 1];
    return max(mx[k][l], mx[k][r-(1<<k)+1]);
}

vector<int> check_validity(int N, std::vector<int> X, std::vector<int> Y,
                                std::vector<int> S, std::vector<int> E,
                                std::vector<int> L, std::vector<int> R){
    add(X); add(Y); add(S); add(E); add(L); add(R); n = N;
    for(int i = 0; i < X.size(); i++){
        g[X[i]].push_back(Y[i]);
        g[Y[i]].push_back(X[i]);
    }
    if(n <= 3000){
        for(int i = 1; i <= n; i++){
            pref[0][i] = suf[n+1][i] = i;
        }
        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= n; j++){
                pref[i][j] = pref[i-1][j];
            }
            for(int to: g[i]){
                if(to < i) join(to, i, pref[i]);
            }
        }
        for(int i = n; i > 0; i--){
            for(int j = 1; j <= n; j++){
                suf[i][j] = suf[i+1][j];
            }
            for(int to: g[i]){
                if(to > i) join(to, i, suf[i]);
            }
        }
        vector<int> ans;
        for(int i = 0; i < S.size(); i++){
            int s = S[i], e = E[i];
            int l = L[i], r = R[i];
            int res = 0;
            for(int k = l; k <= r; k++){
                if(get(s, suf[l]) == get(k, suf[l]) && get(k, pref[r]) == get(e, pref[r])){
                    res = 1;
                }
            }
            ans.push_back(res);
        }
        return ans;
    } else{
        for(int i = 1; i <= n; i++){
            if(g[i].size() == 1){
                dfs(i);
                break;
            }
        }
        for(int i = 2; i <= n; i++){
            lg[i] = lg[i >> 1] + 1;
        }
        for(int k = 1; k <= lg[n]; k++){
            for(int i = 1; i + (1<<k) - 1 <= n; i++){
                mx[k][i] = max(mx[k-1][i], mx[k-1][i+(1<<(k-1))]);
                mn[k][i] = min(mn[k-1][i], mn[k-1][i+(1<<(k-1))]);
            }
        }
        vector<int> ans;
        for(int i = 0; i < S.size(); i++){
            int s = S[i], e = E[i];
            int l = L[i], r = R[i];
            s = b[s]; e = b[e];
            int res = 0;
            if(s <= e){
                int tr = s - 1, tl = e + 1;
                for(int bl = s, br = e; bl <= br;){
                    int mid = (bl + br) >> 1;
                    if(getmn(s, mid) < l) br = mid - 1;
                    else bl = mid + 1, tr = mid;
                }
                for(int bl = s, br = e; bl <= br;){
                    int mid = (bl + br) >> 1;
                    if(getmx(mid, e) > r) bl = mid + 1;
                    else br = mid - 1, tl = mid;
                }
                if(tl <= tr) res = 1;
            } else{
                int tr = e - 1, tl = s + 1;
                for(int bl = e, br = s; bl <= br;){
                    int mid = (bl + br) >> 1;
                    if(getmn(mid, s) < l) bl = mid + 1;
                    else br = mid - 1, tl = mid;
                }
                for(int bl = e, br = s; bl <= br;){
                    int mid = (bl + br) >> 1;
                    if(getmx(e, mid) > r) br = mid - 1;
                    else bl = mid + 1, tr = mid;
                }
                if(tl <= tr) res = 1;
            }
            ans.push_back(res);
        }
        return ans;
    }
}

Compilation message (stderr)

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:52:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |     for(int i = 0; i < X.size(); i++){
      |                    ~~^~~~~~~~~~
werewolf.cpp:77:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |         for(int i = 0; i < S.size(); i++){
      |                        ~~^~~~~~~~~~
werewolf.cpp:106:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |         for(int i = 0; i < S.size(); i++){
      |                        ~~^~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 8 / 8
• Subtask 3: 34 / 34
• Subtask 4: 0 / 51