Submission #1237344

#	Time	Username	Problem	Language	Result	Execution time	Memory
1237344		zadniprovska	Trains (BOI24_trains)	C++20	16 / 100	10 ms	1096 KiB

Main

#include <bits/stdc++.h>

using namespace std;


#define ll long long

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

ll diff[DIM];

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

    ll n;
    cin >> n;


    diff[2] = -1;
    ll dp = 1, answer = 0;
    for (int i=1; i<=n; i++) {
        ll d, x;
        cin >> d >> x;

        // i+d ... i + x*d

        diff[i+d]+=dp;
        diff[i+d] %= mod;
        diff[min(n, i+x*d) + 1]-=dp;
        diff[min(n, i+x*d) + 1] %= mod;
        if (diff[min(n, i+x*d) + 1] < 0) diff[min(n, i+x*d) + 1] += mod;

        answer += dp;
        answer %= mod;

        dp = dp + diff[i+1];
        dp %= mod;
    }

    cout << answer << endl;
    

}
;

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