Submission #809026

#	Time	Username	Problem	Language	Result	Execution time	Memory
809026		math_rabbit_1028	Werewolf (IOI18_werewolf)	C++14	15 / 100	487 ms	287344 KiB

werewolf

#include "werewolf.h"
#include <bits/stdc++.h>
using namespace std;
int n, m, q;
vector<int> adj[202020];

struct disjoint {
    int root[202020], num[202020];
    int r, mn[404040], mx[404040], par[404040];
    vector<int> child[404040];
    int _find(int v) {
        if (v == root[v]) return v;
        else return root[v] = _find(root[v]);
    }
    void _union(int v, int u) {
        v = _find(v);
        u = _find(u);
        if (v == u) return;
        if (v > u) swap(u, v);
        root[u] = v;
        child[r].push_back(num[v]);
        child[r].push_back(num[u]);
        par[num[v]] = par[num[u]] = r;
        mn[r] = min(mn[num[v]], mn[num[u]]);
        mx[r] = max(mx[num[v]], mx[num[u]]);
        num[v] = r;
        r++;
    }

    int ord[808080], lt[404040], rt[404040], s;
    void ett() {
        s = 0;
        DFS(r - 1);
    }
    void DFS(int v) {
        ord[++s] = v;
        lt[v] = s;
        for (int i = 0; i < child[v].size(); i++) {
            int next = child[v][i];
            DFS(next);
            ord[++s] = v;
        }
        rt[v] = s;
    }

    int table[404040][20];
    void sparse() {
        for (int i = 0; i < r; i++) table[i][0] = par[i];
        for (int k = 1; k < 20; k++) {
            for (int i = 0; i < r; i++) {
                if (table[i][k - 1] < 0) table[i][k] = -1;
                else table[i][k] = table[table[i][k - 1]][k - 1];
            }
        }
        /*
        for (int i = 0; i < r; i++) {
            for (int k = 0; k < 20; k++) cout << table[i][k] << " ";
            cout << "\n";
        }
        cout << "\n";
        */
    }

    pair<int, int> get_segment(int st, int limit, int f) {
        if (f) {
            int now = st;
            for (int k = 19; k >= 0; k--) {
                if (table[now][k] != -1 && mn[table[now][k]] >= limit) now = table[now][k];
            }
            return {lt[now], rt[now]};
        }
        else {
            int now = st;
            for (int k = 19; k >= 0; k--) {
                if (table[now][k] != -1 && mx[table[now][k]] <= limit) now = table[now][k];
            }
            return {lt[now], rt[now]};
        }
    }
} left_tree, right_tree;

void make_left_tree() {
    for (int i = 0; i < n; i++) left_tree.root[i] = i;
    for (int i = 0; i < n; i++) left_tree.num[i] = i;
    for (int i = 0; i < n; i++) left_tree.mn[i] = left_tree.mx[i] = i;
    left_tree.r = n;

    for (int i = n - 1; i >= 0; i--) {
        for (int j = 0; j < adj[i].size(); j++) {
            int v = adj[i][j];
            if (v >= i) left_tree._union(i, v);
        }
    }
    left_tree.par[left_tree.r - 1] = -1;
}
void make_right_tree() {
    for (int i = 0; i < n; i++) right_tree.root[i] = i;
    for (int i = 0; i < n; i++) right_tree.num[i] = i;
    for (int i = 0; i < n; i++) right_tree.mn[i] = right_tree.mx[i] = i;
    right_tree.r = n;

    for (int i = 0; i <= n - 1; i++) {
        for (int j = 0; j < adj[i].size(); j++) {
            int v = adj[i][j];
            if (v <= i) right_tree._union(i, v);
        }
    }
    right_tree.par[right_tree.r - 1] = -1;
}

vector<int> ans;
std::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) {
    n = N; m = X.size();
    for (int i = 0; i < m; i++) {
        adj[X[i]].push_back(Y[i]);
        adj[Y[i]].push_back(X[i]);
    }

    make_left_tree();
    left_tree.ett();
    left_tree.sparse();

    make_right_tree();
    right_tree.ett();
    right_tree.sparse();

    q = S.size();
    for (int i = 0; i < q; i++) ans.push_back(0);
    for (int i = 0; i < q; i++) {
        int s = S[i], e = E[i], l = L[i], r = R[i];
        pair<int, int> left_segment = left_tree.get_segment(s, l, 1);
        //cout << left_segment.first << " " << left_segment.second << "\n";
        pair<int, int> right_segment = right_tree.get_segment(e, r, 0);
        //cout << right_segment.first << " " << right_segment.second << "\n";
        int ch[3030];
        for (int j = 0; j < n; j++) ch[j] = 0;
        for (int j = left_segment.first; j <= left_segment.second; j++)
            if (left_tree.ord[j] < n) ch[left_tree.ord[j]] = 1;
        for (int j = right_segment.first; j <= right_segment.second; j++)
            if (right_tree.ord[j] < n && ch[right_tree.ord[j]] == 1) ans[i] = 1;
    }

    return ans;
}

Compilation message (stderr)

werewolf.cpp: In member function 'void disjoint::DFS(int)':
werewolf.cpp:38:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |         for (int i = 0; i < child[v].size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~~~
werewolf.cpp: In function 'void make_left_tree()':
werewolf.cpp:89:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |         for (int j = 0; j < adj[i].size(); j++) {
      |                         ~~^~~~~~~~~~~~~~~
werewolf.cpp: In function 'void make_right_tree()':
werewolf.cpp:103:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |         for (int j = 0; j < adj[i].size(); j++) {
      |                         ~~^~~~~~~~~~~~~~~

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