Submission #1085877

#	Time	Username	Problem	Language	Result	Execution time	Memory
1085877		De3b0o	Trains (BOI24_trains)	C++17	100 / 100	1157 ms	256596 KiB

Main

#include<bits/stdc++.h>
#include<random>
#define ll long long
#define F first
#define S second
#define in insert
#define pb push_back
#define ppb pop_back()
#define d3 ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define cans cout << ans << "\n";
#define yes cout << "Yes" << "\n";
#define no cout << "No" << "\n";
#define pll pair<ll,ll>
#define lin cout << "\n";
#define sqr 340
#define mod 1000000007
#define mid ((l+r)/2)
#define lc (2*x)
#define rc (2*x+1)

using namespace std;

const ll N = 100009;
const ll sz = 40;
vector<ll> seg[sz+1][sz+1];
vector<ll> lazy[sz+1][sz+1];
ll ans[N] , d[N] , x[N];
ll n;
const ll m = 1e9+7;

void se(ll j , ll md , ll x , ll l , ll r , ll l1 , ll r1 , ll val)
{
    if(l>r1||r<l1)
        return;
    if(l>=l1&&r<=r1)
    {
        lazy[j][md][x]=(lazy[j][md][x]+val)%m;
        return;
    }
    se(j,md,lc,l,mid,l1,r1,val);
    se(j,md,rc,mid+1,r,l1,r1,val);
}

ll sg(ll j , ll md , ll x , ll l , ll r , ll idx)
{
    if(l>idx||r<idx)
        return 0;
    if(l==r)
    {
        seg[j][md][x]+=lazy[j][md][x];
        lazy[j][md][x]=0;
        seg[j][md][x]%=m;
        return seg[j][md][x];
    }
    lazy[j][md][lc]=(lazy[j][md][lc]+lazy[j][md][x])%m;
    lazy[j][md][rc]=(lazy[j][md][rc]+lazy[j][md][x])%m;
    lazy[j][md][x]=0;
    return sg(j,md,lc,l,mid,idx) + sg(j,md,rc,mid+1,r,idx);
}

int main()
{
    cin >> n;
    for(int i = 0 ; n>i ; i++)
        cin >> d[i] >> x[i];
    for(int j = 1 ; sz>=j ; j++)
    {
        for(int md = 0 ; j>md ; md++)
        {
            seg[j][md].resize(4*max(1LL,(n-md-1)/j+1));
            lazy[j][md].resize(4*max(1LL,(n-md-1)/j+1));
        }
    }
    ans[0]=1;
    ll an = 0;
    for(int i = 0 ; n>i ; i++)
    {
        for(int j = 1 ; sz>=j ; j++)
        {
            ll md = i%j;
            ans[i]+=sg(j,md,1,0,(n-md-1)/j,i/j);
        }
        ans[i]%=m;
        an+=ans[i];
        an%=m;
        if(d[i]==0)
            continue;
        ll s = min((n-i+1)/d[i],x[i]);
        if(s<=100000/sz)
        {
            for(int j = i+d[i] ; n>j&&x[i]-- ; j+=d[i])
            {
                ans[j]+=ans[i];
                ans[j]%=m;
            }
            continue;
        }
        ll j = d[i];
        ll md = i%j;
        se(j,md,1,0,(n-md-1)/j,i/j,min(i/j+x[i],(n-md-1)/j),ans[i]);
    }
    cout << an;
}

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