Submission #1084754

#	Time	Username	Problem	Language	Result	Execution time	Memory
1084754		zxcigan	Trains (BOI24_trains)	C++17	34 / 100	184 ms	9812 KiB

Main

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
#define int long long
const int N = 2e5;
const int mod = 1e9 + 7;
const int B = 335;
int dp[N];
int32_t main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif // LOCAL
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n;
    cin >> n;
    dp[1] = 1;
    int s = 0;
    vector<vector<int>> add (B + 1, vector<int> (B + 1, 0));
    set<array<int,4>> st;
    for (int i = 1; i <= n; ++i) {
        int x, d;
        cin >> d >> x;
        for (int j = 1; j < B; ++j) {
            (dp[i] += add[j][i % j]) %= mod;
        }
        if (x && d) {
            if (d >= B) {
                for (int j = 1; j <= x; ++j) {
                    if (i + d * j > n) break;
                    (dp[i + d * j] += dp[i]) %= mod;
                }
            } else {
                (add[d][i % d] += dp[i]) %= mod;
                st.insert ({i + x * d + 1, d, i % d, dp[i]});
            }
        }
        while ((int)st.size() && (*st.begin())[0] == i) {
            array<int,4> v = (*st.begin());
            add[v[1]][v[2]] -= v[3];
            while (add[v[1]][v[2]] < 0) add[v[1]][v[2]] += mod;
            st.erase (st.begin());
        }
        (s += dp[i]) %= mod;
    }
    cout << s << '\n';
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 13
• Subtask 3: 0 / 16
• Subtask 4: 34 / 34
• Subtask 5: 0 / 29