Map of STL knowledge summary

1.map It means mapping

Definition ：map<typename1, typename2> m;

Pre mapping types are called keys key, Post type becomes value value

2. Element access

By subscript or iterator

Add ：

The difference in accessing with iterators is , It can be used it->first Access key , use it->second Access value .

map It will automatically sort by the size of the key from small to large .