bool lu(double *a, int *pivot, int n)；矩阵的LU分解。

假设数组an*n在内存中按行优先次序存放，此函数使用高斯列选主元消去法，将其就地进行LU分解。pivot为输出函数.pivot[0,n)中存放主元的位置排列.

函数成功时返回false，否则返回true.





bool guass(double const *lu, int const *p, double *b, int n) 求线性方程组的解。

假设矩阵lum*n为某个矩阵an*n的LU分解，在内存中按行优先次序存放。p[0,n)为LU分解的主元排列。b为方程组Ax=b的右端向量。此函数计算方程组Ax=b的解，并将结果存放在数组b[0,n)中。

函数成功时返回false，否则返回true.-bool lu (double* a, int* pivot, int n)　matrix LU decomposition. Suppose an* n array in memory stored in row order, this function uses the column pivoting Gaussian elimination, LU decomposition of their in situ. pivot for the output function. pivot [0, n) stored in the location of the main element array. function successfully returns false, otherwise true. bool guass (double const* lu, int const* p, double* b, int n)　Linear equations. Suppose matrix lum* n for a matrix of an* n the LU decomposition, in memory stored in row order. p [0, n) for the LU decomposition of the main element array. b for the equation Ax = b of the right end of the vector. This function calculates the equations Ax = b of the solution, and the results stored in array b [0, n) in. Function successfully returns false, otherwise true.