Submission #1186233

#	Time	Username	Problem	Language	Result	Execution time	Memory
1186233		qwusha	Event Hopping (BOI22_events)	C++20	0 / 100	569 ms	46908 KiB

events

#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define int long long
typedef long long ll;
typedef long double ld;
mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
int inf = 1e15;


bool cmp(vector<int> a, vector<int> b) {
    return a[1] < b[1];
}

signed main() {
    int n, q;
    cin >> n >> q;
    vector<pair<int, int>> evinit(n);
    set<int> comst;
    map<int, int> nval, inival;
    for (int i = 0; i < n; i++) {
        cin >> evinit[i].fi >> evinit[i].se;
        comst.insert(evinit[i].fi);
        comst.insert(evinit[i].se);
    }
    int cur = 0;
    for (auto el : comst) {
        nval[el] = cur;
        inival[cur] = el;
        cur++;
    }
    vector<vector<int>> eve(n, vector<int>(3));
    for (int i = 0; i < n; i++) {
        eve[i][0] = nval[evinit[i].fi];
        eve[i][1] = nval[evinit[i].se];
        eve[i][2] = i;
    }
    vector<int> nind(n);
    sort(eve.begin(), eve.end(), cmp);
    for (int i = 0; i < n; i++) {
        nind[eve[i][2]] = i;
    }
    vector<int> ending(cur);
    for (int i = 0; i < n - 1; i++) {
        if (eve[i][1] < eve[i + 1][0]) {
            ending[eve[i][1]] = 1;
        }
    }
    vector<int> pr(cur + 1);
    for (int i = 0; i < cur; i++) {
        pr[i + 1] = ending[i] + pr[i];
    }
    for (int qw = 0; qw < q; qw++) {
        int s, e;
        cin >> s >> e;
        s--;
        e--;
        s = nind[s];
        e = nind[e];
        if (s > e) {
            cout << "impossible" << '\n';
        } else if (pr[eve[e][1]] - pr[eve[s][0]] == 0) {
            cout << e - s << '\n';
        } else {
            cout << "impossible" << '\n';
        }
    }
}

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