一：python官方文档
https://docs.python.org/3.6/library/stdtypes.html#set-types-set-frozenset
二：集合概念
- 集合是无序的
- 集合是无重复元素的
一：add()
会改变原有集合
>>> s = set('HackerRank')
>>> s.add('H')
>>> print s
set(['a', 'c', 'e', 'H', 'k', 'n', 'r', 'R'])
>>> print s.add('HackerRank')#添加后返回none
None
>>> print s
set(['a', 'c', 'e', 'HackerRank', 'H', 'k', 'n', 'r', 'R'])
set.add()
二：pop(),discard(),remove()
- pop()是随机删除元素
- discard(),remove()是删除指定元素的
- discard()在删除不存在元素是不会报错，而remvoe()会报keyerror错误
- 都会改变原有集合
set.pop()
>>> s = set([])
>>> print s.pop() >>> print s
set([])
>>> print s.pop()
KeyError: pop from an empty set
set.pop()
set.remove()
>>> s = set([, , , , , , , , ])
>>> s.remove()
>>> print s
set([, , , , , , , ])
>>> print s.remove()#默认返回None
None
>>> print s
set([, , , , , , ])
>>> s.remove()
KeyError:
set.remove()
set.discard()
>>> s = set([, , , , , , , , ])
>>> s.discard()
>>> print s
set([, , , , , , , ])
>>> print s.discard()
None
>>> print s
set([, , , , , , ])
>>> s.discard()
>>> print s
set([, , , , , , ])
set.discard()
三：intersetcion(),difference(),unoin()，symmetric_difference(),交集，差集，并集,对称差集
不改变原有集合
set.intersection()
>>> s = set("Hacker")
>>> print s.intersection("Rank")
set(['a', 'k'])
>>> print s.intersection(['R', 'a', 'n', 'k'])
set(['a', 'k'])
>>> print s.intersection(enumerate(['R', 'a', 'n', 'k']))
set([])
>>> print s.intersection({"Rank":})
set([])
>>> s & set("Rank")
set(['a', 'k'])
set.intersection()
set.difference()
#set1有的而set2没有的元素
>>> s = set("Hacker")
>>> print s.difference("Rank")
set(['c', 'r', 'e', 'H']) >>> print s.difference(set(['R', 'a', 'n', 'k']))
set(['c', 'r', 'e', 'H']) >>> print s.difference(['R', 'a', 'n', 'k'])
set(['c', 'r', 'e', 'H']) >>> print s.difference(enumerate(['R', 'a', 'n', 'k']))
set(['a', 'c', 'r', 'e', 'H', 'k']) >>> print s.difference({"Rank":})
set(['a', 'c', 'e', 'H', 'k', 'r']) >>> s - set("Rank")
set(['H', 'c', 'r', 'e'])
set.difference()
set.unoin()
>>> s = set("Hacker")
>>> print s.union("Rank")
set(['a', 'R', 'c', 'r', 'e', 'H', 'k', 'n'])
>>> print s.union(set(['R', 'a', 'n', 'k']))
set(['a', 'R', 'c', 'r', 'e', 'H', 'k', 'n'])
>>> print s.union(['R', 'a', 'n', 'k'])
set(['a', 'R', 'c', 'r', 'e', 'H', 'k', 'n'])
>>> print s.union(enumerate(['R', 'a', 'n', 'k']))
set(['a', 'c', 'r', 'e', (, 'a'), (, 'n'), 'H', 'k', (, 'k'), (, 'R')])
>>> print s.union({"Rank":})
set(['a', 'c', 'r', 'e', 'H', 'k', 'Rank'])
>>> s | set("Rank")
set(['a', 'R', 'c', 'r', 'e', 'H', 'k', 'n'])
set.union()
set.symmetric_difference()
>>> s = set("Hacker")
>>> print s.symmetric_difference("Rank")
set(['c', 'e', 'H', 'n', 'R', 'r'])
>>> print s.symmetric_difference(set(['R', 'a', 'n', 'k']))
set(['c', 'e', 'H', 'n', 'R', 'r'])
>>> print s.symmetric_difference(['R', 'a', 'n', 'k'])
set(['c', 'e', 'H', 'n', 'R', 'r'])
>>> print s.symmetric_difference(enumerate(['R', 'a', 'n', 'k']))
set(['a', 'c', 'e', 'H', (, 'R'), 'r', (, 'n'), 'k', (, 'a'), (, 'k')])
>>> print s.symmetric_difference({"Rank":})
set(['a', 'c', 'e', 'H', 'k', 'Rank', 'r'])
>>> s ^ set("Rank")
set(['c', 'e', 'H', 'n', 'R', 'r'])
set.symmertic_difference
四：update(),difference_update(),set.symmetric_difference_update()
set.update(set2):以集合2还更新集合1，加入到集合1中
>> myset.update([, , , ]) # update() only works for iterable objects
>> myset
{'a', , 'c', 'b', , , (, ), }
>> myset.update({, , })
>> myset
{'a', , 'c', 'b', , , , , (, ), }
>> myset.update({, }, [, ])
>> myset
{'a', , 'c', 'b', , , , , , , (, ), , }
set.update()
set.difference_update(set2):用set1-set2来更新set1，覆盖set1值
#用A,B的差集来更新A
>>> H = set("Hacker")
>>> R = set("Rank")
>>> H.difference_update(R)
>>> print H
set(['c', 'e', 'H', 'r'])
set.difference——update()
set.symmetric_difference_update(set2):用set1和set2的对称差集来更新set1，覆盖set1的值
#用A,b互相差集来更新A
>>> H = set("Hacker")
>>> R = set("Rank")
>>> H.symmetric_difference_update(R)
>>> print H
set(['c', 'e', 'H', 'n', 'r', 'R'])
set.systemeratic_update()
五：isdisjoint(), issubset(), issuperset()
set.isdisjoint():如果两个集合没有交集则返回True。
s1,s2={,,},{,,}s1.isdisjoint(s2)True
set.isdisjoint()
issubset():是否为子集
-
issubset(other)¶ set <= other-
Test whether every element in the set is in other.
set < other：严格子集-
Test whether the set is a proper subset of other, that is,
set <= other and set != other
>>> set1={,,,,}
>>> set2={,,,,,}
>>> set1.issubset(set2)
True
>>> set3={,,,,,}
>>> set3.issubset(set2)
True
>>> set3<set2
False
>>> set1<set2
True
-
issuperset(other)¶ set >= other-
Test whether every element in other is in the set.
set > other：严格父集-
Test whether the set is a proper superset of other, that is,
set >= other and set != other.
a = set(input().split())
print(all(a > set(input().split()) for _ in range(int(input()))))