Submission #1288188

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288188		vulestamenkovic	Trains (BOI24_trains)	C++20	100 / 100	173 ms	253268 KiB

Main

#include<bits/stdc++.h>
#define int long long
#define MAXN (int)1e5+5
#define MAXS 320
using namespace std;
const int mod=1e9+7;
int d[MAXN],x[MAXN],p[MAXN][MAXS],dp[MAXN];
void solve() {
    int n;cin>>n;
    for(int i=1;i<=n;i++){
        cin>>d[i]>>x[i];
        dp[i]=1;
    }
    for(int j=1;j*j<=n;j++){
        p[n][j]=1;
    }
    for(int i=n-1;i>=1;i--){
        if(d[i]){
            if(d[i]*d[i]<=n){
                if(i+d[i]<=n){
                    dp[i]+=(p[i+d[i]][d[i]]-p[min(i+(x[i]+1)*d[i],n+1)][d[i]]+mod)%mod;
                    dp[i]%=mod;
                }
            }else{
                for(int j=1;j<=x[i]&&i+j*d[i]<=n;j++){
                    dp[i]=(dp[i]+dp[i+j*d[i]])%mod;
                }
            }
        }
        for(int j=1;j*j<=n;j++){
            p[i][j]=dp[i]+(i+j<=n?p[i+j][j]:0ll);
        }
    }
    cout<<dp[1]<<'\n';
}
int32_t main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int32_t T=1;//cin>>T;
    while(T--) {
        solve();
    }
    return 0;
}

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