哥德巴赫猜想，4~1000=素数之和并输出

# include <stdio.h>
int su(int a)
{
	int b,i;
     b = 0;
	for (i = 2;i <= a / 2;i++)
	{
		if (a % i == 0)
		{
			b = 1;
			break;
		}
	}
	return b;
}

int main()
{
	int i, j,a;
	for (i = 4;i <= 1000;i = i + 2)
	{
		for (j=2;j<=i/2;j++)
		{
			a = i - j;
			if (su(j) == 0 && su(a) == 0)
			{
				printf("%d=%d+%d\n", i, j, i - j);
				break;
			}
		}
	}
	return 0;
}