UVa1471 LIS变种 nlgn

//#include<bits/stdc++.h>
#include<stdio.h>
#include<algorithm>
#include<queue>
#include<string.h>
#include<iostream>
#include<math.h>
#include<set>
#include<map>
#include<vector>
#include<iomanip>
using namespace std;
#define ll long long
#define pb push_back

const int maxn=2e5+9;
int f[maxn];//以i开头的长度
int g[maxn];//以i结尾的长度
int d[maxn];
const int inf=0x3f3f3f3f;
int arr[maxn];

int main(){
int T;
scanf("%d",&T);
while(T--){
int n;
scanf("%d",&n);
for(int i=1;i<=n;i++)scanf("%d",&arr[i]);

f[1]=1;
for(int i=2;i<=n;i++){
if(arr[i]>arr[i-1])f[i]=f[i-1]+1;
else f[i]=1;
}
g
=1;
for(int i=n-1;i>=1;i--){
if(arr[i]<arr[i+1])g[i]=g[i+1]+1;
else g[i]=1;
}

int ans=0;
for(int i=1;i<=n;i++)d[i]=inf;//长度i的头所需代价
for(int i=1;i<=n;i++){
int len=(lower_bound(d+1,d+1+i,arr[i])-(d+1))+g[i];
ans=max(ans,len);
d[f[i]]=min(arr[i],d[f[i]]);
}
printf("%d\n",ans);
}
}