请问这个枚举是啥意思
enum code{a = 1 << 0,b = 1 << 1,c = 1 << 2,d = 1 << 3,e = 1 << 4,f = 1 << 5,g = 1 << 6,MAX = 7};
enum code{a = 1,b = 2,c = 4,d = 8,e = 16,f = 32,g = 64,MAX = 7};