java求1-1/2! +1/3! -... -1/10! 利用简单的for循环即可

Question

java求1-1/2! +1/3! -... -1/10! 利用简单的for循环即可

Answer 1

代码如下：

public class TEST {
	
	public static double jiecheng(int n){
		double s = 1;
		for(int i = 1; i <=n;i++)
			s *= i;
		return s;
	}
	public static double sum(int n){
		double sum = 0.0;
		int s = 1;
		for(int i = 1; i <=n; i++){
			sum += s/jiecheng(i);
			s = -s;
		}
		return sum;
	}
	
	
	public static void main(String[] args) throws Exception 
	{
		int n = 10;
		double ss = sum(n);
		System.out.println(ss);
		
		
	}
	
	
}