Submission #1093445

#	Time	Username	Problem	Language	Result	Execution time	Memory
1093445		raphaelp	Trains (BOI24_trains)	C++14	100 / 100	215 ms	9940 KiB

Main

#include <bits/stdc++.h>
using namespace std;
int main()
{
    long long N;
    cin >> N;
    long long MOD = 1000000007;
    vector<long long> D(N), X(N);
    for (long long i = 0; i < N; i++)
    {
        cin >> D[i] >> X[i];
    }
    vector<long long> dp(N, 0);
    dp[0] = 1;
    vector<vector<long long>> ST(sqrt(N) + 1);
    for (long long i = 1; i <= sqrt(N); i++)
    {
        ST[i].assign(i, 0);
    }
    priority_queue<vector<long long>> PQ;
    long long tot = 0;
    for (long long i = 0; i < N; i++)
    {
        for (long long j = 1; j <= sqrt(N); j++)
        {
            dp[i] = (dp[i] + ST[j][i % j]) % MOD;
        }
        tot = (tot + dp[i]) % MOD;
        if (D[i] > sqrt(N))
        {
            long long temp = i;
            for (long long j = 0; j < X[i]; j++)
            {
                temp += D[i];
                if (temp >= N)
                    break;
                dp[temp] = (dp[temp] + dp[i]) % MOD;
            }
        }
        else if (D[i] != 0)
        {
            ST[D[i]][i % D[i]] = (ST[D[i]][i % D[i]] + dp[i]) % MOD;
            PQ.push({-(i + X[i] * D[i]), D[i], dp[i]});
        }
        while (!PQ.empty() && -PQ.top()[0] <= i)
        {
            ST[PQ.top()[1]][i % PQ.top()[1]] = (ST[PQ.top()[1]][i % PQ.top()[1]] + MOD - PQ.top()[2]) % MOD;
            PQ.pop();
        }
    }
    cout << tot;
}

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