| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1047750 | modwwe | Sequence (APIO23_sequence) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
//https://www.instagram.com/_modwwe/
#pragma GCC optimize("Ofast,unroll-loops")
#include<bits/stdc++.h>
//#define int long long
//#define ll long long
#define down cout<<'\n';
#define debug cout<<" cucuucucuuu",down
#define NHP ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out","w",stdout)
#define pb push_back
#define checktime cerr << (double)clock() / CLOCKS_PER_SEC * 1000 << " ms";
using namespace std;
void phongbeo();
const int inf=1e9;
const int mod2=1e9+7;
const int mod1=998244353;
struct icd
{
long double a;
int b;
};
struct ib
{
int a;
int b;
};
struct ic
{
int a,b,c;
};
struct id
{
int a,b,c,d;
};
struct ie
{
int a,b,c,d,e;
};
int n,m,s1,s2,s4,s3,sf,k,s5,s6,mx,s7,s8,s9,mx2,res,dem2=0,dem=0,s33,dem3,l,r,mid;
int i,s10,s12;
int kk;
int el=29;
main()
{
#ifndef ONLINE_JUDGE
fin(task),fou(task);
#endif
NHP
/// cin>>s1;
// modwwe
phongbeo();
}
ib mer(ib a,ib b)
{
return {max(a.a,b.a),min(a.b,b.b)};
}
struct IT
{
ib t[2000005];
int t2[2000005];
int t3[2000005];
void build(int node,int l,int r)
{
if(l==r)
{
t[node]= {n-l+1,n-l+1};
return;
}
int mid=l+r>>1;
build(node<<1,l,mid);
build(node<<1|1,mid+1,r);
t[node]=mer(t[node<<1],t[node<<1|1]);
}
void ff(int x)
{
for(int i=x*2; i<=x*2+1; i++)
t[i].a+=t2[x],
t[i].b+=t2[x],
t2[i]+=t2[x],
t3[i]+=t3[x],
t[i].a+=t3[x],
t[i].b-=t3[x];
t2[x]=0;
t3[x]=0;
}
void upd(int node,int l,int r,int l1,int r1,int x)
{
if(l>r1||r<l1) return;
if(l>=l1&&r<=r1)
{
t[node].a+=x;
t[node].b+=x;
t2[node]+=x;
return;
}
if(t2[node]!=0||t3[node]!=0) ff(node);
int mid=l+r>>1;
upd(node<<1,l,mid,l1,r1,x);
upd(node<<1|1,mid+1,r,l1,r1,x);
t[node]=mer(t[node<<1],t[node<<1|1]);
}
void upd2(int node,int l,int r,int l1,int r1,int x)
{
if(l>r1||r<l1) return;
if(l>=l1&&r<=r1)
{
t[node].a+=x;
t[node].b-=x;
t3[node]+=x;
return;
}
if(t2[node]!=0||t3[node]!=0) ff(node);
int mid=l+r>>1;
upd2(node<<1,l,mid,l1,r1,x);
upd2(node<<1|1,mid+1,r,l1,r1,x);
t[node]=mer(t[node<<1],t[node<<1|1]);
}
ib get(int node,int l,int r,int l1,int r1)
{
if(l>r1||r<l1) return {-inf,inf};
if(l>=l1&&r<=r1) return t[node];
if(t2[node]!=0||t3[node]!=0) ff(node);
int mid=l+r>>1;
return mer(get(node<<1,l,mid,l1,r1),get(node<<1|1,mid+1,r,l1,r1));
}
} st;
vector<int> v[500002];
int sequence(int x,vector<int>_a)
{
n=x;
for(int i=0; i<x; i++)
v[_a[i]].pb(i+1);
st.build(1,1,n+1);
s4=0;
for(int i=1; i<=n; i++)
{
v[i].pb(n+1);
dem=0;
for(int j=0; j<v[i].size()-1; j++)
{
int x=v[i][j];
int x2=v[i][j+1];
st.upd(1,1,n+1,1,x,-1);
ib xx=st.get(1,1,n+1,x,x2);
st.upd2(1,1,n+1,1,x,1);
l=1;
r=x;
while(l<=r)
{
int mid=l+r>>1;
ib xc=st.get(1,1,n+1,1,mid);
if(xc.a-xx.b>=0&&xc.b-xx.a<=0)r=mid-1;
else l=mid+1;
}
dem++;
s2=lower_bound(v[i].begin(),v[i].end(),r+1)-v[i].begin();
s4=max(s4,dem-s2);
}
for(int j=0; j<v[i].size()-1; j++)
{
x=v[i][j];
st.upd(1,1,n+1,1,x,-1);
st.upd2(1,1,n+1,1,x,-1);
}
}
return s4;
}
void phongbeo()
{
cin>>n;
vector<int> a(n);
for(int i=0; i<n; i++)
cin>>a[i];
cout<<sequence(n,a);
}