Submission #1027524

#	Time	Username	Problem	Language	Result	Execution time	Memory
1027524		stdfloat	Boat (APIO16_boat)	C++17	9 / 100	2106 ms	233276 KiB

boat

#include <bits/stdc++.h>
using namespace std;

using ll = long long;

const int md = (int)1e9 + 7;

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);

    int n;
    cin >> n;

    vector<int> a(n), b(n);
    for (int i = 0; i < n; i++) cin >> a[i] >> b[i];

    map<int, int> m;
    for (int i = 0; i < n; i++) {
        // cout << "\ni " << i << '\n'; 

        int x = (m.empty() || a[i] <= (*m.begin()).first ? 0 : (*--m.lower_bound(a[i])).second);
        if (m.find(a[i]) == m.end()) m[a[i]] = x;
        for (int j = a[i] + 1; j <= b[i]; j++) {
            if (m.find(j) == m.end()) m[j] = m[j - 1];
        }
        int sm = 0;
        for (int j = a[i]; j <= b[i]; j++) {
            int y = m[j];

            sm = (sm + x + 1) % md;
            m[j] = (m[j] + sm) % md;

            // cout << "j " << j << ' ' << y << ' ' << m[j] << ' ' << x << '\n';

            x = y;
        }

        auto t = m.upper_bound(b[i]);
        while (t != m.end()) {
            m[(*t).first] = (m[(*t).first] + sm) % md; t++;
        }
    }

    cout << (*--m.end()).second << '\n';

    // int sm = 0;
    // for (auto i : m) sm = (sm + i.second) % md;

    // cout << sm << '\n';
}

/*sub1
vector<int> dp(n);
for (int i = 0; i < n; i++) {
    dp[i] = 1;
    for (int j = 0; j < i; j++) {
        if (a[j] < a[i]) dp[i] = (dp[i] + dp[j]) % md;
    }
}

int sm = 0;
for (auto i : dp) sm = (sm + i) % md;

cout << sm;
*/

• Subtask 1: 9 / 9
• Subtask 2: 0 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42