The C++ source code of IGTOA (an improved GTOA) for TSP

The C++ source code of IGTOA in “An efficient method for solving TSP using improved group theory-based optimization algorithm and fragment exchange strategy”《一种采用改进群论优化算法（Improved Group Theory-based Optimization Algorithm, IGTOA）与片段交换策略求解旅行商问题（Traveling Salesman Problem, TSP）的高效方法》一文中的IGTOA的C++源代码