Submission #1014764

#	Time	Username	Problem	Language	Result	Execution time	Memory
1014764		Warinchai	Trains (BOI24_trains)	C++14	100 / 100	356 ms	505784 KiB

Main

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int s=317;
int dp[200005][s+5];
int sum1[200005][s+5];
int sum2[200005];
int ans=0;
int md=1e9+7;
int32_t main(){
    //cerr<<"work\n";
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;cin>>n;
    sum2[1]=1;
    for(int i=1;i<=n;i++){
        //cerr<<i<<"\n";
        int d,x;cin>>d>>x;
        //x=min(x,(long long)1e5);
        int tans=0;
        for(int j=1;j<=s;j++){
            if(i-j>=1)sum1[i][j]=sum1[i-j][j]+dp[i][j]+md,sum1[i][j]%=md;
            tans+=sum1[i][j];
            tans%=md;
        }
        //cerr<<tans<<" ";
        tans+=sum2[i];
        tans%=md;
        //cerr<<tans<<"\n";
        ans+=tans;
        ans%=md;
        if(d==0||x==0)continue;
        if(d<=s){
            if(i+d>n)continue;
            dp[i+d][d]+=tans;
            dp[i+d][d]%=md;
            if(i+(x+1)*d<=n)dp[i+(x+1)*d][d]-=tans,dp[i+(x+1)*d][d]%=md;
        }else{
            for(int j=1;(j<=x)&&(i+j*d<=n);j++){
                sum2[i+j*d]+=tans;
                sum2[i+j*d]%=md;
            }
        }
    }
    cout<<ans;
}

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