parallel conjugate gradient solver

This is a conjugate gradient solver for large sparse matrix. ie, to get x in Ax = b. Read data from "matrix", save result in "ans".

generate N*N matrix

	python Random_matrix.py N

serial algorithm

	g++ CPU_Conjugate.cpp -o cpu_conjugate
	./cpu_conjugate N -t -d

parallel algorithm

	mpic++ MPI_Conjugate.cpp -o mpi_conjugate
	mpiexec -n 2 ./mpi_conjugate N -t -d

validate if the result is right

	g++ Validation.cpp -o validation
	./validation