编程序，按如下要求来求解n元一次线性方程组（假设方程组具有唯一解）。

（1）方程个数n之值由用户通过键盘输入；

（2）方程组存放在“增广矩阵”A之中，而n行n+1列的A存储空间通过new来动态分配，且A的各元素值也由用户通过键盘输入；

（3）方程组的解存放于“向量”B之中，而具有n个元素的B存储空间也通过new来动态分配。

-programmed by the following demands to solve an n-linear equation (equation with the assumption that the only solution). (1) Equation Number n value by the user through the keyboard input; (2) equations stored in the "Augmented Matrix" A, n and n an OK A new storage space by dynamically allocated, A and the value of each element by the user through the keyboard input; (3) equations that are stored in the "vector" B, and n elements of B storage space through to the new dynamic allocation.