제출 #896762

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
896762		juliany2	Event Hopping 2 (JOI21_event2)	C++17	100 / 100	131 ms	27084 KiB

event2

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) (x).begin(), (x).end()

const int N = 2e5 + 7, L = 20;
int n, k;
array<int, 2> a[N];
int lift[N][L];

int main() {
    cin.tie(0)->sync_with_stdio(false);

    cin >> n >> k;

    vector<int> srt = {0};
    for (int i = 1; i <= n; i++) {
        cin >> a[i][0] >> a[i][1];
        srt.push_back(a[i][0]);
        srt.push_back(a[i][1]);
    }

    sort(all(srt));
    srt.erase(unique(all(srt)), srt.end());

    int m = srt.size();

    for (int i = 1; i <= m; i++)
        lift[i][0] = m + 1;
    fill(lift[m + 1], lift[m + 1] + L, m + 1);

    for (int i = 1; i <= n; i++) {
        a[i][0] = lower_bound(all(srt), a[i][0]) - srt.begin();
        a[i][1] = lower_bound(all(srt), a[i][1]) - srt.begin();

        lift[a[i][0]][0] = min(lift[a[i][0]][0], a[i][1]);
    }

    for (int i = m - 1; i >= 0; i--) {
        lift[i][0] = min(lift[i][0], lift[i + 1][0]);
        for (int j = 1; j < L; j++)
            lift[i][j] = lift[lift[i][j - 1]][j - 1];
    }

    auto query = [&](int l, int r) {
        int ret = 0;
        for (int i = L - 1; i >= 0; i--)
            if (lift[l][i] <= r)
                l = lift[l][i], ret += (1 << i);
        return ret;
    };

    int cnt = query(1, m);
    vector<int> ans;
    set<int> cov = {0, m};
    for (int i = 1; i <= n; i++) {
        if (*cov.lower_bound(a[i][0]) < a[i][1] || ans.size() == k)
            continue;

        int l = *prev(cov.lower_bound(a[i][0])) + 1, r = *cov.lower_bound(a[i][1]);
        int cur = cnt - query(l, r) + query(l, a[i][0]) + query(a[i][1], r);
        if (cur + ans.size() + 1 >= k) {
            ans.push_back(i);
            cnt = cur;
            for (int j = a[i][0]; j < a[i][1]; j++)
                cov.insert(j);
        }
    }

    if (ans.size() < k)
        cout << -1 << '\n';
    else {
        for (int i : ans)
            cout << i << '\n';
    }

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

event2.cpp: In function 'int main()':
event2.cpp:57:63: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   57 |         if (*cov.lower_bound(a[i][0]) < a[i][1] || ans.size() == k)
      |                                                    ~~~~~~~~~~~^~~~
event2.cpp:62:34: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   62 |         if (cur + ans.size() + 1 >= k) {
      |             ~~~~~~~~~~~~~~~~~~~~~^~~~
event2.cpp:70:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   70 |     if (ans.size() < k)
      |         ~~~~~~~~~~~^~~

• Subtask 1: 7 / 7
• Subtask 2: 1 / 1
• Subtask 3: 31 / 31
• Subtask 4: 61 / 61