Submission #781939

#	Time	Username	Problem	Language	Result	Execution time	Memory
781939		themm1	Event Hopping (BOI22_events)	C++17	0 / 100	152 ms	9108 KiB

events

#include <bits/stdc++.h>
using namespace std;
// ordered set whith s.order_of_key(x) method, which returns rank of element x in set s
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
*/

// pair printing
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "(" << par.first << "; " << par.second << ")"; return out;}
// set printing
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for(const auto &x:cont) out << x << ", "; out << "}"; return out; }
// map printing
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for(const auto &x:cont) out << x << ", "; out << "}"; return out; }
// unordered_set printing
template <class T>
ostream& operator<<(ostream& out, const unordered_set<T> &cont) {out << "{";for(const auto &x:cont) out << x << ", ";out << "}";return out;}
// unordered_map printing
template <class T, class U>
ostream& operator<<(ostream& out, const unordered_map<T, U> &cont) {out << "{";for(const auto &x:cont) out << x << ", ";out << "}";return out;}
// vector printing
template<class T>
ostream& operator<<(ostream& out, const vector<T> &cont){ out << "[";  for (const auto &x:cont) out << x << ", ";  out << "]"; return out;}

#define print(x) cout << (x) << endl;
#define dmp(x) cerr << #x << " = " << x << endl
#define dmpn(x) cerr << #x << " = " << x << "; "
#define dmpl(x) cerr << "Line " << __LINE__ << ": " << #x << " = " << x << endl

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define pb push_back
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()
#define contains(s,x) ((s).find(x) != (s).end())

int N, Q;

struct interval {
        int index = -1;
        int s = -1, e = -1;
        int pindex = -1;
};

bool compare(interval &a, interval &b) {
        return a.s < b.s;
}

bool compare2(interval &a, interval &b) {
        return a.e < b.e;
}

ostream& operator<<(ostream& out, const interval &i) {
        out << "{" << i.s << "; " << i.e << "}"; return out;
}

void solve() {
        cin >> N >> Q;
        vector<interval> v, iv;
        for (int i = 0; i < N; i++) {
                int a, b;
                cin >> a >> b;
                v.pb({ i, a, b });
                iv.pb({ i, a, b });
        }
        sort(all(v), compare);

        interval next = v[0];
        int i = 1;
        while (i < N && v[i - 1].s == v[i].s) {
                if (v[i].e > next.e) next = v[i];
                i++;
        }
        vector<interval> p = { next };
        vector<int> borders;
        while (i < N) {
                // dmp(v[i]);
                next = v[i];
                int j = i + 1;
                while (j < N && p.back().e >= v[j].s) {
                        if (v[j].e > next.e) next = v[j];
                        j++;
                }
                if (next.s > p.back().e) {
                        borders.pb(p.back().e);
                        borders.pb(v[j - 1].s);
                }
                if (next.e > p.back().e) p.pb(next);
                i = j;
        }
        for (int i = 0; i < sz(p); i++) {
                p[i].pindex = i;
                iv[p[i].index].pindex = i;
        }
        for (int i = 0; i < N; i++) {
                v[i].pindex = iv[v[i].index].pindex;
        }
        // dmp(borders);

        sort(all(v), compare2);
        vector<int> best(N);
        int j = 0;
        for (int i = 0; i < N; i++) {
                if (j < sz(p) - 1 && p[j + 1].s <= v[i].e) j++;
                best[v[i].index] = j;
        }
        // dmp(p);
        // dmp(best);
        while (Q--) {
                int s, e;
                cin >> s >> e;
                s--;
                e--;
                int l = upper_bound(all(borders), v[s].e) - begin(borders);
                int r = (--upper_bound(all(borders), v[e].s)) - begin(borders);
                // dmpn(l); dmp(r);
                // medzi intervalmi je medzera
                if (r > l) {
                        cout << "impossible" << endl;
                // prvy interval sa konci neskor ako druhy
                } else if (iv[s].e > iv[e].e) {
                        cout << "impossible" << endl;
                // druhy interval sa zacina skor ako sa prvy skonci
                } else if (iv[s].e >= iv[e].s) {
                        cout << 1 << endl;
                } else {
                        int a = p[best[iv[s].index]].pindex - (iv[s].index != best[iv[s].index]);
                        int b = p[best[iv[e].index]].pindex + (iv[e].index != best[iv[e].index]);
                        // dmpn(a); dmp(b);
                        cout << b - a - 1 << endl;
                }
        }
}

int32_t main() {
        ios::sync_with_stdio(false);
        cin.tie(0);

        int t = 1;
        // cin >> t;
        while (t--) {
                solve();
        }
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30