QOJ.ac
QOJ
ID | Submission ID | Problem | Hacker | Owner | Result | Submit time | Judge time |
---|---|---|---|---|---|---|---|
#823 | #569429 | #9314. The Median of the Median of the Median | 22016020736 | 22016020736 | Failed. | 2024-09-16 23:52:21 | 2024-09-16 23:52:21 |
Details
Extra Test:
Accepted
time: 0ms
memory: 3600kb
input:
4 3 8 8 2
output:
3
result:
ok 1 number(s): "3"
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#569429 | #9314. The Median of the Median of the Median | 22016020736 | AC ✓ | 539ms | 35276kb | C++14 | 2.1kb | 2024-09-16 22:44:20 | 2024-09-18 18:11:57 |
answer
#include <bits/stdc++.h>
using namespace std;
void solve(){
int n;cin>>n;
vector<int>a(n+1);
map<int,int>idx,val;int cnt=0;
for(int i=1;i<=n;++i)cin>>a[i],idx[a[i]]=1;
for(auto &[i,j]:idx)j=++cnt,val[cnt]=i;
vector<vector<int>>b(n+1,vector<int>(n+1,0));
vector<int>tree(n*4,0);
function<void(int,int,int)>init=[&](int id,int l,int r){
tree[id]=0;
if(l==r)return;
int mid=(l+r)>>1;
init(id<<1,l,mid);
init(id<<1|1,mid+1,r);
};
function<void(int,int,int,int)>add=[&](int id,int l,int r,int p){
if(l==r)tree[id]++;
else{
int mid=(l+r)>>1;
if(p<=mid)add(id<<1,l,mid,p);
else add(id<<1|1,mid+1,r,p);
tree[id]=tree[id<<1]+tree[id<<1|1];
}
};
function<int(int,int,int,int)>query=[&](int id,int l,int r,int k){
if(l==r)return l;
int mid=(l+r)>>1;
if(k<=tree[id<<1])return query(id<<1,l,mid,k);
else return query(id<<1|1,mid+1,r,k-tree[id<<1]);
};
for(int l=1;l<=n;++l){
for(int r=l;r<=n;++r){
add(1,1,cnt,idx[a[r]]);
b[l][r]=query(1,1,cnt,(r-l+2)>>1);
}
init(1,1,cnt);
}
auto b1=b;
int l=1,r=cnt;
int bound=n*(n+1)>>1;
bound=(bound+1)>>1;
function<bool(int)>check=[&](int x){
for(int i=0;i<=n;++i)
for(int j=0;j<=n;++j)
b1[i][j]=0;
for(int l=1;l<=n;++l)
for(int r=1;r<=n;++r)
if(b[l][r]>x)b1[l][r]=1;
for(int i=1;i<=n;++i)
for(int j=1;j<=n;++j)
b1[i][j]=b1[i][j]+b1[i-1][j]+b1[i][j-1]-b1[i-1][j-1];
int res=0;
for(int l=1;l<=n;++l)
for(int r=l;r<=n;++r){
int len=r-l+1,sum=len*(len+1)/2;
if(sum-(b1[r][r]-b1[l-1][r])>=(sum+1)/2)res++;
}
return res>=bound;
};
while(l<r){
int mid=(l+r)>>1;
if(check(mid))r=mid;
else l=mid+1;
}
cout<<val[l]<<"\n";
}
signed main()
{
solve();
return 0;
}