高斯列主元消去法求解线性方程组,文档用了两种方法实现方程组的求解，含代码。-Out PCA Gaussian elimination method for solving linear equations

要求编写高斯消去法求解线性方程组的函数和 要求编写列主元法函数，并在高斯消去法函数中由用户选择是否采用列主元法。 -Require written Gaussian elimination method for solving linear equations and functions require writing columns PCA function and Gaussian elimination function selected by the user is using