1996608_ac_171ms_124k.cpp

北大大牛代码 1240道题的原代码 超级权威

# include <iostream>
# include <vector>
# include <cmath>

using namespace std;

int min(int a,int b)
{
	return a<b?a:b;
}

bool check(int a, int b)
{
	for(int i = 2; i <= min(a,b); i++)
		if(a%i==0&&b%i==0)
			return false;
	return true;
}

int main()
{
	int N;
	vector<int> a;

	while(cin>>N&&N)
	{
		int no = 0;
		a.resize(N+1);
		for(int i = 0; i < N; i++)
			cin>>a[i];
		for(i = 0; i < N-1; i++)
			for(int j = i+1; j < N; j++)
			{
				if(check(a[i],a[j]))
			    	no++;
			}
		if(no==0)
			printf("No estimate for this data set.\n");
		else
			printf("%lf\n",sqrt(3.0*N*(N-1)/no));
	}
	return true;
}