mysqrt.java

来自「是<java程序设计>的课后作业2-8源码.可以供初学者参考,作了解」· Java 代码 · 共 45 行

/**
 * @(#)MySqrt.java
 *
 *
 * @author 
 * @version 1.00 2009/3/12
 */

public class MySqrt {
        
    /**
     * Creates a new instance of <code>MySqrt</code>.
     */
    public MySqrt() {
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        double n=2.0;
        double result=sqrt(n);
        System.out.println(result);
    }
    
    public static double sqrt(double Num)
    {
    	if(Num==0)
    		return 0;
    	double last=0;
    	double next=Num;
    	while(Math.abs(next-last)>1e-6)
    	{
    		last=next;
    		next=(last+(Num/last))/2;
    		//观察运行结果,实际中可以注释
    		System.out.println(last+"  "+next);
    		
    	}
    	
    	return next;
    }
}