Submission #1111552

#	Time	Username	Problem	Language	Result	Execution time	Memory
1111552		kxd	Trains (BOI24_trains)	C++17	21 / 100	2067 ms	4856 KiB

Main

#include <bits/stdc++.h>
//#define DEBUG 1106
#define int long long
#define ll long long
#define ld long double
#define pb emplace_back
#define p_q priority_queue
#define m_p make_pair
#define pii pair<int,int>
#define endl '\n'
#define INIT ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define FOR(i,a,b) for(int i = a; i <= b; i++)
#define forn(i,n) for (int i = 0; i < n; i++)
#define forn1(i,n) for (int i = 1; i <= n; i++)
#define all(x) x.begin(),x.end()
#define ft first
#define sd second
#define lowbit(x) (x&(-x))
#define chmax(x,y) x=max(x,y)
#define chmin(x,y) x=min(x,y)
#ifdef DEBUG
#define debug(x) cout << #x << ": " << x << endl;
#else
#define debug(x) 1106;
#endif

using namespace std;
const int N = 2e5+5;
const int inf = 1e9;
const int INF = 1e18;
const int MOD = 1e9+7;

int d[N], x[N];
int a[N];

signed main() {
	INIT
	#ifdef DEBUG
	freopen("input.txt", "r", stdin);
	#endif
	///////////
	int n;
	cin >> n;
	forn(i,n) {
		cin >> d[i] >> x[i];
	}
	a[0] = 1;
	forn(i,n) {
		if(d[i]==0) continue;
		forn1(j,x[i]) {
			if(i+j*d[i]>=n) break;
			a[i+j*d[i]] += a[i];
			a[i+j*d[i]] %= MOD;
		}
	}
	int ans = 0;
	forn(i,n) {
		//cout << a[i] << ' ';
		ans += a[i];
		ans = ans%MOD;
	}
	//cout << '>';
	cout << (ans+MOD+MOD)%MOD;
}

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