Submission #700246

#	Time	Username	Problem	Language	Result	Execution time	Memory
700246		LeVanThuc	Discharging (NOI20_discharging)	C++17	9 / 100	1079 ms	54700 KiB

Discharging

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
#define p(x,y) pair<ll,ll>(x,y)
#define BIT(i,x) ((x>>i)&1)
#define MASK(x) (1<<x)
#define ld long double
#define __builtin_popcount __builtin_popcountll
#define pll pair<ll,ll>
template<class T1,class T2>
bool maximize(T1 &x,const T2 &y)
{
    if(x<y)
    {
        x=y;
        return 1;
    }
    return 0;
}
template<class T1,class T2>
bool minimize(T1 &x,const T2 &y)
{
    if(x>y)
    {
        x=y;
        return 1;
    }
    return 0;
}
void online()
{
    std::ios_base::sync_with_stdio(0);
    cin.tie(0);
#ifndef ONLINE_JUDGE
//    freopen("input.inp", "r", stdin);
//    freopen("output.out","w", stdout);
#else
#endif
}
static const ll N=1e6+10,M=1e16;
ll n,m,A,B,a[N],b[N],f[N];
struct SegmentTree
{
    vector<ll> Tree;
    ll n;
    SegmentTree(ll _n=0)
    {
        n=_n;
        Tree.resize(4*n+1);
    }
    ll update(ll i,ll l,ll r,ll pos,ll vl)
    {
        if(r<pos||pos<l) return Tree[i];
        if(l==r) return Tree[i]=vl;
        return Tree[i]=max(update(i*2,l,(l+r)/2,pos,vl),update(i*2+1,(l+r)/2+1,r,pos,vl));
    }
    ll query(ll i,ll l,ll r,ll l1,ll r1)
    {
        if(r1<l||r<l1) return 0;
        if(l1<=l&&r<=r1) return Tree[i];
        return max(query(i*2,l,(l+r)/2,l1,r1),query(i*2+1,(l+r)/2+1,r,l1,r1));
    }
}S;
ll c(ll l,ll r)
{
    return S.query(1,1,n,l,r)*(n-l+1);
}
int main()
{
    online();
    cin>>n;
    S=SegmentTree(n);
    for(ll i=1;i<=n;i++)
    {
        cin>>a[i];
        S.update(1,1,n,i,a[i]);
    }
    f[0]=0;
    vector<pll> vt;
    vt.emplace_back(0,0);
    ll ans=M;
    for(ll i=1;i<=n;i++)
    {
        auto best=lower_bound(vt.begin(),vt.end(),p(i+1,0));
        best--;
        auto x=*best;
        ll k=x.se;
        f[i]=f[k]+c(k+1,i);
        for(ll j=vt.size()-1;j>=0;j--)
        {
            if(f[vt[j].se]+c(vt[j].se+1,vt[j].fi)>f[i]+c(i+1,vt[j].fi))
            {
                vt.pop_back();
            }
            else
            {
                ll b=vt[j].se,d=n/2+1;
                while(d)
                {
                    while(b+d<=n&&f[vt[j].se]+c(vt[j].se+1,b+d)<=f[i]+c(i+1,b+d)) b+=d;
                    d/=2;
                }
                b++;
                if(b!=n+1)
                {
                    vt.emplace_back(b,i);
                }
                break;
            }
        }
        if(vt.empty()) vt.emplace_back(1,i);
//        for(auto v:vt) cout<<"("<<v.fi<<","<<v.se<<") ";
//        cout<<'\n';
    }
    cout<<f[n];
}

Compilation message (stderr)

Discharging.cpp: In function 'int main()':
Discharging.cpp:83:8: warning: unused variable 'ans' [-Wunused-variable]
   83 |     ll ans=M;
      |        ^~~

• Subtask 1: 9 / 9
• Subtask 2: 0 / 13
• Subtask 3: 0 / 25
• Subtask 4: 0 / 11
• Subtask 5: 0 / 14
• Subtask 6: 0 / 28