Submission #1111077

#	Time	Username	Problem	Language	Result	Execution time	Memory
1111077		huantran	Osumnjičeni (COCI21_osumnjiceni)	C++17	110 / 110	209 ms	34644 KiB

Main

#include <bits/stdc++.h>

using namespace std;
using ll = long long int;
const int maxn = 2e5 + 5;
const int oo = 1e9 + 7;
const ll inf = 1e18;

int n, q;
int l[maxn], r[maxn];
int up[maxn][22];
set<pair<int, int>> left_boud;

int can_add(int idx) {
    if (left_boud.empty())
        return 1;
    
    auto it = left_boud.lower_bound({l[idx], 0});
    if (it != left_boud.end()) {
        int id = (*it).second;
        if (r[idx] >= l[id])
            return 0;
    }

    if (it != left_boud.begin()) {
        it--;
        int id = (*it).second;
        if (r[id] >= l[idx])
            return 0;
    }
    return 1;
}

int get_ans(int u, int v) {
    int ans = 0;
    for (int len = 21; len >= 0; len--) {
        if (up[u][len] <= v) {
            u = up[u][len];
            ans += (1 << len);
        }
    }

    return (ans + 1);
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);

    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> l[i] >> r[i];
    }

    int nxt = 1;
    for (int i = 1; i <= n; i++) {
        while (nxt <= n && can_add(nxt))
            left_boud.insert({l[nxt], nxt}), nxt++;
        
        up[i][0] = nxt;
        left_boud.erase({l[i], i});
    }

    up[n + 1][0] = n + 1;
    for (int len = 1; len < 22; len++) {
        for (int i = 1; i <= n + 1; i++) {
            up[i][len] = up[up[i][len - 1]][len - 1];
        }
    }

    cin >> q;

    while (q--) {
        int p, q;
        cin >> p >> q;
        cout << get_ans(p, q) << '\n';
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 50 / 50