Submission #1002240

#	Time	Username	Problem	Language	Result	Execution time	Memory
1002240		Valters07	Trains (BOI24_trains)	C++17	100 / 100	159 ms	127060 KiB

Main

#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
#define fio ios_base::sync_with_stdio(0);cin.tie(0);
#define en cin.close();return 0;
#define ll long long
#define fi first
#define se second
using namespace std;
const int N = 1e5+5;
const int SQ = sqrt(N)+2;
const int mod = 1e9+7;
int pf[N][SQ], dp[N];
int sum(int a, int b)
{
    a+=b;
    if(a>=mod)
        a-=mod;
    if(a<0)
        a+=mod;
    return a;
}
int mul(int a, int b)
{
    return 1ll*a*b%mod;
}
int main()
{
    fio
//    ifstream cin("in.in");
    int n;
    cin >> n;
    int sq = sqrt(n), res = 0;
    dp[1]=1;
    for(int i = 1;i<=n;i++)
    {
        for(int j = 1;j<=sq;j++)
        {
            if(i-j>=0)
                pf[i][j]=sum(pf[i][j],pf[i-j][j]);
            dp[i]=sum(dp[i],pf[i][j]);
        }
        res=sum(res,dp[i]);
        int d, x;
        cin >> d >> x;
        if(!d)
            continue;
        if(d>sq)
        {
            for(int j = 1;j<=x&&i+j*d<=n;j++)
                dp[i+j*d]=sum(dp[i+j*d],dp[i]);
        }
        else
        {
            if(i+d<=n)
                pf[i+d][d]=sum(pf[i+d][d],dp[i]);
            if(i+1ll*(x+1)*d<=n)
                pf[i+(x+1)*d][d]=sum(pf[i+(x+1)*d][d],-dp[i]);
        }
    }
    cout << res;
    return 0;
}

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