Submission #1051451

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051451		pravcoder	Trains (BOI24_trains)	C++14	21 / 100	2074 ms	2396 KiB

Main

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> v2i;
typedef pair<int, int> pi;
typedef vector<ll> vl;

#define pb push_back
#define mp make_pair
#define rep(i, n) for (int i = 0; i < n; i++)

const ll p = 1e9 + 7;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	int n, di, xi;
	vl d, x;

	cin >> n;
	rep(i, n) {
		cin >> di >> xi;
		d.pb(di); x.pb(xi);
	}

	vl dp = { 1 };

	ll total = 1;

	for (int i = 1; i < n; i++)
	{
		ll t = 0;
		for (int j = 0; j < i; j++)
		{
			if (d[j] != 0) {
				if ((i-j) % d[j] == 0 && i-j <= d[j] * x[j]) {
					t += dp[j];
					t %= p;
					//cout << i << " can be reached by " << j << "\n";
				}
			}
		}
		dp.pb(t);
		total += t;
		total %= p;
		//cout << "calculated " << i << " as " << t << "\n";
	}

	cout << total;

	return 0;
}

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