ProjectEuler_2

i=2_sum=0a={0:1,1:2}                 #you cannot give value to a index that not exist in Listwhile True:    a[i]=a[i-1]+a[i-2]    if a[i]>4000000:         #break condition            break    if (i%3==1):         #only this item is even-valued         _sum+=a[i]    i+=1    print _sum+2

这代码龊的一比啊，这是在写C语言吧，靠。弄了两个pythonic的代码来学习下。

s = 0a, b = 1, 1while a < 4000000:    a, b = b, a+b    if a%2 == 0:        s += aprint s

 

a = [1,2]i = 2while a[-1] < 4000000:    a.append(a[i-2] + a[i-1])    i += 1print sum(filter(lambda x: x%2 == 0, a))

这两段都是阿三哥写的，转自PE的论坛，hk97和hkapur97。