You can download, build, and run the programs with the following commands:

$ export GOPATH=$HOME/yourdir # choose workspace directory
// change to above directory
$ go get github.com/raj-chak/golang_parallel_compute        # fetch
$ go build github.com/raj-chak/golang_parallel_compute/parallel  # build
$ ./parallel
3.141592654423124