STL中map用法详解：map的构造函数、数据的插入、map的大小、数据的遍历、数据的查找（包括判定这个关键字是否在map中出现）等。-Detailed the STL map usage: traversal, find the data constructor map, insert the data, the size of the map, data (including determining whether the keyword appears in the map) and th