第三章 41題

<span style="font-size:18px;">#include<stdio.h>
#include<math.h>    
int prim(int num)    
{    
    int i,j=0;    
	for(i=2;i<=sqrt(num);i++)    
	{    
		if(num%i==0)    
			j++;    
	}    
	if(j==0)    
		return 1;    
	else    
		return 0;    
} 
int main()
{
	int a,k;
	printf("請輸入一個大於2的偶數:");    
    scanf("%d",&a);    
	
    for(k=2;k<=a/2;k++)    
    {    
        if(prim(k)&&prim(a-k))   
			
			
			printf("%d=%d+%d\n",a,k,a-k); } 
	
	return 0;
}</span>

<img src="https://img-blog.csdn.net/20150528231012941?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvd3d3X2JpMTIxOA==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />