LightOJ

来源:互联网 发布:海岛奇兵神像升级数据 编辑:程序博客网 时间:2024/06/13 20:17

Bamboo Pole-vault is a massively popular sport in Xzhiland. And Master Phi-shoe is a very popular coach for his success. He needs some bamboos for his students, so he asked his assistant Bi-Shoe to go to the market and buy them. Plenty of Bamboos of all possible integer lengths (yes!) are available in the market. According to Xzhila tradition,

Score of a bamboo = Φ (bamboo's length)

(Xzhilans are really fond of number theory). For your information, Φ (n) = numbers less than n which are relatively prime (having no common divisor other than 1) to n. So, score of a bamboo of length 9 is 6 as 1, 2, 4, 5, 7, 8 are relatively prime to 9.

The assistant Bi-shoe has to buy one bamboo for each student. As a twist, each pole-vault student of Phi-shoe has a lucky number. Bi-shoe wants to buy bamboos such that each of them gets a bamboo with a score greater than or equal to his/her lucky number. Bi-shoe wants to minimize the total amount of money spent for buying the bamboos. One unit of bamboo costs 1 Xukha. Help him.

Input

Input starts with an integer T (≤ 100), denoting the number of test cases.

Each case starts with a line containing an integer n (1 ≤ n ≤ 10000) denoting the number of students of Phi-shoe. The next line contains n space separated integers denoting the lucky numbers for the students. Each lucky number will lie in the range [1, 106].

Output

For each case, print the case number and the minimum possible money spent for buying the bamboos. See the samples for details.

Sample Input

3

5

1 2 3 4 5

6

10 11 12 13 14 15

2

1 1

Sample Output

Case 1: 22 Xukha

Case 2: 88 Xukha

Case 3: 4 Xukha

题意:给你一组数字,让你求欧拉函数的值大于等于它的数的和的最小值;

思路:第一种方法不难,重点是第二种方法的学习;

第一种:素数的euler应该是相同euler值最小值,只需要筛查素数就可已,euler(n)=n-1;

第二种,素数筛法预处理,用a数组替换后面euler值比较小的,用b数组表示euler值与最小下标的一个映射;

#include<cstdio>#include<cstring>#include<algorithm>using namespace std;const int max_n=2000010;int a[max_n+5],b[max_n+5];void Init()//euler筛法 {a[1]=0;    for(int i=2;i<=max_n;i++)    a[i]=i;for(int i=2;i<max_n;i++){if(a[i]==i){for(int j=i;j<max_n;j+=i)a[j]=a[j]/i*(i-1);}}}int main(){int T,n,k;long long ans;    Init();memset(b,0,sizeof(b));for(int i=1;i<=max_n;i++) a[i]=max(a[i],a[i-1]);//不可省略 for(int i=max_n;i>=1;i--) b[a[i]]=i;for(int i=1;i<=max_n;i++){if(b[i]==0){int t=i;while(b[i]==b[t] && t<=max_n){t++;}b[i]=b[t];}}b[0]=0;scanf("%d",&T);while(T--){static int cnt=0;ans=0;scanf("%d",&n);while(n--){scanf("%d",&k);ans+=b[k];}printf("Case %d: %lld Xukha\n",++cnt,ans);}    return 0;}


原创粉丝点击