用显示格式的中心差分方法求解热传导方程，用C++编程，数据用TECplot等图像显示软件显示。边界条件：条件：-10<x<10,正三角形位于-0.5 <x <0.5 -Display format with a central difference method for solving the heat conduction equation, with C++ programming, data and other image display software wi