6.1 函数（1）（素数、牛顿迭代法求平方根）

我就是我 2022-05-20 08:26 295阅读 0赞

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#include<iostream>
    using namespace std;
    int Max(int x, int y)
    {
    	if(x > y) 
    		return x;
    	else 
    		return y;
    }
    int main()
    {
    	int n = Max(4,6);//6 
    	cout << n << "," << Max(20,n) << endl;//6,20
    	return 0;
    }

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#include<iostream>
    #include<cmath>
    using namespace std;
    bool Isprime(unsigned int n)//无符号整数，一定为正数
    {
    	if(n <=1 ) 
    		return false;
    	for(int i = 2; i <= sqrt(n); ++i)
    	{
    		if(n % i == 0)
    			return false;
    	}
    	return true;
    }
    int main()
    {
    	 cout << Isprime(2) << "," << Isprime(4) << "," << Isprime(5);//1,0,1 
    	 return 0; 
    }

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#include<iostream>
    #define EPS 0.001//精度
    using namespace std;
    double Sqrt(double a)
    {
    	double x = a/2, lastx = x + 1 + EPS;
    	while(x - lastx > EPS || lastx - x < EPS)//|x-lastx|>EPS大于精度范围，就要继续迭代 
    	{
    		lastx = x;
    		x = (x + a/x)/2;
    	}
    	return x; 
    }
    double Distance(double x1, double y1, double x2, double y2)
    {
    	return Sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
    } 
    int main()
    {
    	double x1, y1, x2, y2, x3, y3;
    	cin >> x1 >> y1 >> x2 >> y2 >> x3 >> y3;
    	cout << Distance(x1,y1,x2,y2) << endl;
    	cout << Distance(x1,y1,x3,y3) << endl;
    	cout << Distance(x2,y2,x3,y3) << endl;
    	return 0;
    }

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