Submission #1051323

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051323		Malix	Trains (BOI24_trains)	C++14	37 / 100	99 ms	3932 KiB

Main

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef pair<int,int> pi;
typedef vector<pi> pii;
typedef tuple<int,int,int> tii;
typedef vector<ll> li;
typedef vector<li> lii;
 
#define REP(i,a,b) for(int i=a;i<b;i++)
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define LSOne(s) ((s)&(-s))
 
ll INF=1e18+10;
int inf=1e9+10;
ll M=1e9+7;

int main() {   
// ios::sync_with_stdio(0);
// cin.tie(0);
    int n;cin>>n;
    pii a(n);
    REP(i,0,n)cin>>a[i].F>>a[i].S;
    vector<ll> ans(n,0);
    ans[0]=1;
if(n<=10000){
    REP(i,0,n){
        int k=a[i].F;
        if(k==0)continue;
        REP(j,1,a[i].S+1){
            if(i+j*k>=n)break;
            ans[i+j*k]+=ans[i];
            ans[i+j*k]%=M;
        }
    }
    ll val=0;
    REP(i,0,n){
        val+=ans[i];
        val%=M;
    }
    cout<<val;
    return 0;
}
    ll b=1;
    vector<ll> c(n,0);
    c[min(n-1,a[0].S)]=1;
    REP(i,1,n){
        ans[i]+=b;
        ans[i]%=M;
        b-=c[i];
        b+=M;
        b%=M;
        if(a[i].S!=0){
            c[min(n-1,i+a[i].S)]+=ans[i];
            c[min(n-1,i+a[i].S)]%=M;
            b+=ans[i];
            b%=M;
        }
    }
    ll val=0;
    REP(i,0,n){
        val+=ans[i];
        val%=M;
    }
    cout<<val;
}

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