这是用C++实现的ID3决策树，决策树算法是非常常用的分类算法，是逼近离散目标函数的方法，学习得到的函数以决策树的形式表示。-ID3 decision tree, the decision tree algorithm implementation in C++ is a very commonly used classification algorithms, approximation discrete objective function, the learning function to the form of a decision tree.