标签：nbsp desc logs script always bsp while ade use
Description
Eric has a long rope whose length is N, now he wants to mark on the rope with different colors. The way he marks the rope is:
1. He will choose a color that hasn’t been used
2. He will choose a length L (N>L>1) and he defines the mark’s value equals L
3. From the head of the rope, after every L length, he marks on the rope (you can assume the mark’s length is 0 )
4.
When he chooses the length L in step 2, he has made sure that if he
marks with this length, the last mark will be at the tail of the rope
Eric
is a curious boy, he want to choose K kinds of marks. Every two of the
marks’ value are coprime(gcd(l1,l2)=1). Now Eric wants to know the max
K. After he chooses the max K kinds of marks, he wants to know the max
sum of these K kinds of marks’ values.
You can assume that Eric always can find at least one kind of length to mark on the rope.
Solution
质因数分解一下就好了，应该是道模板题
然而我忘记还有质因数只有一个的情况，L不能等于N啊
QvQ拍了好久都没找到错在哪，后来随手输了个1024发现事情有蹊跷…
#include<iostream> #include<cstdio> #include<cstring> #include<cstdlib> #include<vector> #include<map> using namespace std; typedef long long LL; LL T,ans=0; vector<LL>v; map<LL,LL>num; LL gcd(LL a,LL b) { return b?gcd(b,a%b):a; } LL mul(LL a,LL b,LL p) { LL res=0; while(b) { if(b&1)res=(res+a)%p; a=(a+a)%p;b>>=1; } return res; } LL pow(LL a,LL n,LL p) { LL res=1; while(n) { if(n&1)res=mul(res,a,p); a=mul(a,a,p);n>>=1; } return res; } bool check(LL a,LL n,LL m,LL cnt) { LL x=pow(a,m,n),y=x; for(int i=1;i<=cnt;i++) { x=mul(x,x,n); if(x==1&&y!=1&&y!=x-1)return 1; y=x; } return x!=1; } bool Miller_Rabin(LL n) { if(n==2)return 1; if(n<=1||n&1==0)return 0; LL m=n-1,cnt=0; while(m&1==0)cnt++,m>>=1; for(int i=1;i<=7;i++) { if(check(rand()%(n-1)+1,n,m,cnt)) return 0; } return 1; } LL rho(LL n,LL c) { LL i=1,k=2,x=rand()%(n-1)+1,y=x,d; while(1) { x=(mul(x,x,n)+c)%n; d=x>y?gcd(x-y,n):gcd(y-x,n); if(d>1)return d; if(y==x)return n; if(i==k)y=x,k<<=1; i++; } } void solve(LL n) { if(n==1)return; if(Miller_Rabin(n)) { if(!num[n]) {v.push_back(n),ans++,num[n]=1;} num[n]*=n; return; } LL p=n; while(p==n)p=rho(n,rand()%(n-1)+1); solve(p);solve(n/p); } int main() { scanf("%lld",&T); while(T--) { LL n; scanf("%lld",&n); v.clear(),num.clear(),ans=0; solve(n); if(v[0]==n)ans--; printf("%lld ",ans); LL sum=0; for(int i=0;i<ans;i++) sum+=num[v[i]]; if(ans==1)sum/=v[0]; printf("%lld\n",sum); } return 0; }
[HDU 4344]Mark the Rope（Pollard_rho+Miller_Rabin）
标签：nbsp desc logs script always bsp while ade use
原文地址：http://www.cnblogs.com/Zars19/p/6840576.html
