2020牛客寒假算法基础集训营6 E.立方数（唯一分解定理 素数筛）

https://ac.nowcoder.com/acm/contest/3007/E

放下题解

 #include<bits/stdc++.h>
 using namespace std;
 typedef long long ll;
 const int maxn = ;
 ll vis[maxn*],prime[maxn],prime_3[maxn];
 ll tot = ;
 void getPrime(){
     memset(vis,,sizeof(vis));
     for(ll i=;i<=maxn;i++){
         if(!vis[i])prime[tot++]=i,prime_3[tot-] = i*i*i;
         for(ll j=;j<tot;j++){
             if(prime[j]*i>maxn)break;
             vis[prime[j]*i]=;
             if(i%prime[j]==)break;
         }
     }
 }

 int main(){
     getPrime();
     int t;scanf("%d",&t);
     while(t--){
         ll n;
         ll ans = ;
         scanf("%lld",&n);
         for(int i = ;i<tot&&prime[i]<=n;i++){
             while(n%prime_3[i] == ){
                 ans *=prime[i];
                 n/=prime_3[i];
             }
             while(n%prime[i] == ){
                 n/=prime[i];
             }
         }
         int L = , R = ;
         while(L<=R){//二分试除
             int mid = (L+R)/;
             if((ll)mid*mid*mid<n) L = mid + ;
             else R = mid - ;
         }
         if((ll)L*L*L == n) ans*=L;
         printf("%lld\n",ans);
     }
     return ;
 }