链接:https://codeforces.ml/contest/1350/problem/B
There are nn models in the shop numbered from 11 to nn, with sizes s1,s2,…,sns1,s2,…,sn.
Orac will buy some of the models and will arrange them in the order of increasing numbers (i.e. indices, but not sizes).
Orac thinks that the obtained arrangement is beatiful, if for any two adjacent models with indices ijij and ij+1ij+1 (note that ij<ij+1ij<ij+1, because Orac arranged them properly), ij+1ij+1 is divisible by ijij and sij<sij+1sij<sij+1.
For example, for 66 models with sizes {3,6,7,7,7,7}{3,6,7,7,7,7}, he can buy models with indices 11, 22, and 66, and the obtained arrangement will be beautiful. Also, note that the arrangement with exactly one model is also considered beautiful.
Orac wants to know the maximum number of models that he can buy, and he may ask you these queries many times.
Input
The first line contains one integer t (1≤t≤100)t (1≤t≤100): the number of queries.
Each query contains two lines. The first line contains one integer n (1≤n≤100000)n (1≤n≤100000): the number of models in the shop, and the second line contains nn integers s1,…,sn (1≤si≤109)s1,…,sn (1≤si≤109): the sizes of models.
It is guaranteed that the total sum of nn is at most 100000100000.
Output
Print tt lines, the ii-th of them should contain the maximum number of models that Orac can buy for the ii-th query.
Example
input
Copy
4 4 5 3 4 6 7 1 4 2 3 6 4 9 5 5 4 3 2 1 1 9
output
Copy
2 3 1 1
Note
In the first query, for example, Orac can buy models with indices 22 and 44, the arrangement will be beautiful because 44 is divisible by 22 and 66 is more than 33. By enumerating, we can easily find that there are no beautiful arrangements with more than two models.
In the second query, Orac can buy models with indices 11, 33, and 66. By enumerating, we can easily find that there are no beautiful arrangements with more than three models.
In the third query, there are no beautiful arrangements with more than one model.
代码:
#include<iostream>
#include<cstring>
#include<cstdio>
#include<queue>
#include<cstdlib>
#include<cmath>
#include<stack>
#include<map>
#include<algorithm>
using namespace std;
#define ll long long
#define lb long double
#define INF 0x3f3f3f3f
#define maxn 200010
ll n,k,l,t,x,s;
ll a[200001];
ll dp[100001];
vector<ll>m[100001];
int main()
{
cin>>t;
for(int i=2;i<=100000;i++)
{
x=sqrt(i);
for(int j=1;j<=x;j++)
{
if(i%j==0)
{
m[i].push_back(j);
if(j*j!=i&&j!=1)
m[i].push_back(i/j);
}
}
}
while(t--)
{
cin>>n;
for(int i=1;i<=n;i++)
{
cin>>a[i];
dp[i]=1;
}
s=1;
for(int i=2;i<=n;i++)
{
for(int j=0;j<m[i].size();j++)
{
//cout<<m[i][j]<<" ";
if(a[i]>a[m[i][j]])
dp[i]=max(dp[i],dp[m[i][j]]+1);
}
//cout<<endl;
s=max(s,dp[i]);
}
cout<<s<<endl;
}
}