Submission #1051521

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051521		Malix	Trains (BOI24_trains)	C++14	34 / 100	213 ms	504488 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 n;
vector<ll> dp;
vi d,x;
int m;
int dd=1e5;
 
int main() {   
// ios::sync_with_stdio(0);
// cin.tie(0);
    cin>>n;
    d.resize(n);x.resize(n);
    REP(i,0,n)cin>>d[i]>>x[i];
    m=sqrt(n)+1;
    ll ans=0;
    vector<ll> val(n,0);
    val[0]=1;
    vector<vector<ll>> arr(n,vector<ll>(m,0));
    vector<vector<ll>> arr2(n,vector<ll>(m,0));
    REP(i,0,n){
        REP(j,1,m){
            if(arr[i][j]==0)continue;
            val[i]+=arr[i][j];
            val[i]%=M; 
            arr[i][j]-=arr2[i][j];
            if(i+j<n)arr[i+j][j]=(arr[i][j]-arr2[i][j])%M;
        }
        if(d[i]==0)continue;
        if(d[i]<m){
            if(i+d[i]<n){
                arr[i+d[i]][d[i]]+=val[i];
                arr[i+d[i]][d[i]]%=M;
            }
            ll k=(ll)i+(ll)d[i]*(ll)x[i];
            if(k<(ll)n){
                arr2[i+d[i]*x[i]][d[i]]+=val[i];
                arr2[i+d[i]*x[i]][d[i]]%=M;
            }
        }
        else{
            REP(j,1,x[i]+1){
                if(i+d[i]*j>=n)break;
                val[i+d[i]*j]+=val[i];
                val[i+d[i]*j]%=M;
            }
        }
    }
    REP(i,0,n){
        ans+=val[i];
        ans%=M;
    }
    cout<<ans;
}

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