stl中map用法（Map usage in STL）.docVIP

stl中map用法（Map usage in STL） STL map usage detailed, -C++ name library, 2009-09-07, 21:03STL, map usage detailed Since STL is a unified whole, many uses of map are combined with other things in STL; map Because it is ordered internally and is guaranteed by the red black tree, the time complexity of many functions is log2N if map is used Function can be achieved, and STL Algorithm can also complete this function, it is recommended to use map own function, efficient one Some...... Map is an associative container for STL, which provides one to one (the first one can be called a keyword, each keyword) A data processing capability that occurs only once in map, second values that might be called the keyword, and because of this feature, it Completion is possible to provide quick access to programming while we are dealing with one to one data. Here says the map internal data Organization, map internal self built a red black tree (a non balanced balance of the two tree), the tree with automatic sorting of data Function, so all data within the map is in order, and we see the benefits of ordering in the back. The following example illustrates what is one to one data mapping. For example, in a class, each students student number and his name exist With a mapping relationship, this model can be easily described by map. It is obvious that student ID is described by int, and characters are represented by strings (this article does not use char * to describe strings, but uses string to describe them in STL). Here is the map description Code: Mapint, string, mapStudent; 1. map constructor Map provides a total of 6 constructors, which relate to memory allocator, which are skipped, and we will contact below To some map construction methods, what were going to say here is that we usually construct a map with the following methods: Mapint, string, mapStudent; 2. insertion of data After constructing the map container, we can insert data into it. Here are three ways to insert data: The fi