、哥赫巴德猜想是任一大于 2 的偶数都可写成两个质数之和。请编写程序验证 100 之 内大于 2 的偶数符合哥赫巴德猜想。运行效果如下: 提示:定义并调用 isprime 函数判断是否质数，每行显示五个式子，每个式子的整数显示两位，每个式子后面显示 tab(\t)。

代码如下：

def isprime(num):
    if num <= 1:
        return False
    for i in range(2, int(num**0.5)+1):
        if num % i == 0:
            return False
    return True

for i in range(4, 101, 2):
    for j in range(2, i//2+1):
        if isprime(j) and isprime(i-j):
            print("{:02d} = {:02d} + {:02d}\t".format(i, j, i-j), end="")
            break
    if (i-2) % 10 == 0:
        print()

运行结果如下：

04 = 02 + 02	06 = 03 + 03	08 = 03 + 05	10 = 03 + 07	12 = 05 + 07	
14 = 03 + 11	16 = 03 + 13	18 = 05 + 13	20 = 03 + 17	22 = 05 + 17	
24 = 05 + 19	26 = 07 + 19	28 = 05 + 23	30 = 07 + 23	32 = 11 + 21	
34 = 07 + 27	36 = 05 + 31	38 = 07 + 31	40 = 11 + 29	42 = 05 + 37	
44 = 07 + 37	46 = 11 + 35	48 = 13 + 35	50 = 07 + 43	52 = 11 + 41	
54 = 13 + 41	56 = 05 + 51	58 = 11 + 47	60 = 07 + 53	62 = 17 + 45	
64 = 07 + 57	66 = 11 + 55	68 = 13 + 55	70 = 11 + 59	72 = 13 + 59	
74 = 19 + 55	76 = 13 + 63	78 = 17 + 61	80 = 11 + 69	82 = 19 + 63	
84 = 13 + 71	86 = 19 + 67	88 = 17 + 71	90 = 11 + 79	92 = 19 + 73	
94 = 19 + 75	96 = 13 + 83	98 = 19 + 79	100 = 17 + 83