stl set的使用

1. set之间的比较

StandardC++LibraryReference

<set> Members

Operators

operator!=	Tests if the set or multiset object on the left side of the operator is not equal to the set or multiset object on the right side.
operator<	Tests if the set or multiset object on the left side of the operator is less than the set or multiset object on the right side.
operator<=	Tests if the set or multiset object on the left side of the operator is less than or equal to the set or multiset object on the right side.
operator==	Tests if the set or multiset object on the left side of the operator is equal to the set or multiset object on the right side.
operator>	Tests if the set or multiset object on the left side of the operator is greater than the set or multiset object on the right side.
operator>=	Tests if the set or multiset object on the left side of the operator is greater than or equal to the set or multiset object on the right side.

Specialized Template Functions

swap	Exchanges the elements of two sets or multisets.

Classes

set Class	Used for the storage and retrieval of data from a collection in which the values of the elements contained are unique and serve as the key values according to which the data is automatically ordered.
multiset Class	Used for the storage and retrieval of data from a collection in which the values of the elements contained need not be unique and in which they serve as the key values according to which the data is automatically ordered.

2．Set支持的一些操作

注意，set不支持像vector一样的下标[]操作，如果想遍历元素，只能使用iterator来实现。

StandardC++LibraryReference

set Members

Typedefs

allocator_type	A type that represents the allocator class for the set object.
const_iterator	A type that provides a bidirectional iterator that can read a const element in the set.
const_pointer	A type that provides a pointer to a const element in a set.
const_reference	A type that provides a reference to a const element stored in a set for reading and performing const operations.
const_reverse_iterator	A type that provides a bidirectional iterator that can read any const element in the set.
difference_type	A signed integer type that can be used to represent the number of elements of a set in a range between elements pointed to by iterators.
iterator	A type that provides a bidirectional iterator that can read or modify any element in a set.
key_compare	A type that provides a function object that can compare two sort keys to determine the relative order of two elements in the set.
key_type	The type describes an object stored as an element of a set in its capacity as sort key.
pointer	A type that provides a pointer to an element in a set.
reference	A type that provides a reference to an element stored in a set.
reverse_iterator	A type that provides a bidirectional iterator that can read or modify an element in a reversed set.
size_type	An unsigned integer type that can represent the number of elements in a set.
value_compare	The type that provides a function object that can compare two elements to determine their relative order in the set.
value_type	The type describes an object stored as an element of a set in its capacity as a value.

Member Functions

begin	Returns an iterator that addresses the first element in the set.
clear	Erases all the elements of a set.
count	Returns the number of elements in a set whose key matches a parameter-specified key.
empty	Tests if a set is empty.
end	Returns an iterator that addresses the location succeeding the last element in a set.
equal_range	Returns a pair of iterators respectively to the first element in a set with a key that is greater than a specified key and to the first element in the set with a key that is equal to or greater than the key.
erase	Removes an element or a range of elements in a set from specified positions or removes elements that match a specified key.
find	Returns an iterator addressing the location of an element in a set that has a key equivalent to a specified key.
get_allocator	Returns a copy of the allocator object used to construct the set.
insert	Inserts an element or a range of elements into a set.
key_comp	Retrieves a copy of the comparison object used to order keys in a set.
lower_bound	Returns an iterator to the first element in a set with a key that is equal to or greater than a specified key.
max_size	Returns the maximum length of the set.
rbegin	Returns an iterator addressing the first element in a reversed set.
rend	Returns an iterator that addresses the location succeeding the last element in a reversed set.
set	Constructs a set that is empty or that is a copy of all or part of some other set.
size	Returns the number of elements in the set.
swap	Exchanges the elements of two sets.
upper_bound	Returns an iterator to the first element in a set that with a key that is equal to or greater than a specified key.
value_comp	Retrieves a copy of the comparison object used to order element values in a set.

2. 向set插入的数据，默认会自动按照升序排列