Codeforces Round #162 (Div. 1) B. Good Sequences (dp+分解素数)

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
#include<cmath>
#include<iostream>
#include<map>
#define mod 1000007
#define maxn 200001
usingnamespace std;
typedef longlong ll;
ll a[maxn];
ll dp[maxn];
ll n;
int main(){
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>a[i]; 
    } 
    for(int i=0;i<n;i++){
        ll z=a[i];
        map<ll,ll> mp;
        vector<int> q;
            while(z!=1){
                ll t=(ll)sqrt((double)z);//必须要加，不然会超时
                ll j=2;
                for(;j<=t;j++){
                    if(z%j==0){
                        if(mp[j]==0) q.push_back(j);
                        mp[j]++;    
                        z/=j;
                        break;
                    }
                }
                if(j==t+1){
                    if(mp[z]==0) q.push_back(z);//判断素数情况
                    break;
                }
            }
        ll mx=-1;
        for(int j=0;j<q.size();j++){//找出最大长度
            dp[q[j]]++;
            if(mx==-1) mx=dp[q[j]];
            else mx=max(mx,dp[q[j]]);
        }
        for(int j=0;j<q.size();j++){//重新赋到每一个位置
            dp[q[j]]=mx;
        }
    }
    ll x=dp[0];
    for(int i=0;i<maxn;i++){
        x=max(x,dp[i]);
    }
    cout<<max((ll)1,x);
}