Submission #1237386

#	Time	Username	Problem	Language	Result	Execution time	Memory
1237386		zadniprovska	Trains (BOI24_trains)	C++20	71 / 100	2095 ms	4936 KiB

Main

#include <bits/stdc++.h>

using namespace std;


#define ll int
#define pll pair<ll, ll>

const ll DIM = 1e5 + 7;
const ll mod = 1e9 + 7;
const ll sq = 400;

ll dp[DIM];
map<pll, ll> s;
vector< pair<pll, ll> > er[DIM];

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

    ll n;
    cin >> n;


    dp[1] = 1;
    for (int i=1; i<=n; i++) {
        ll d, x;
        cin >> d >> x;

        for (auto [p, val] : er[i]) {
            s[p] -= val;
            if (s[p] < 0) s[p] += mod;
        }

        for (auto [p, val] : s) {
            if (i%p.first == p.second) {
                dp[i] += val;
                dp[i] %= mod;
            }
        }

        if (d == 0) continue;

        x = min(x, (n-i)/d);

        if (x <= sq) {
            for (int j=i+d; j<=i + x*d; j+=d) {
                dp[j] += dp[i];
                dp[j] %= mod;
            }
        }
        else {
            s[{d, i%d}] += dp[i];
            s[{d, i%d}] %= mod;

            er[i + x*d + 1].push_back({{d, i%d}, dp[i]});
        }
    }


    ll answer = 0;
    for (int i=1; i<=n; i++) {
        answer += dp[i];
        answer %= mod;
    }
    cout << answer << endl;
    

}
;

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