rosalind.info problem #1 parallel solution

dna.go

package main

import (
        "fmt"
        "io/ioutil"
        "runtime"
)

func baseCountWork(data []byte, baseChan chan [4]int64) {
        var bases [4]int64
        for _, ch := range data {
                switch ch {
                        case 'A', 'a':
                                bases[0]++
                        case 'G', 'g':
                                bases[1]++
                        case 'C', 'c':
                                bases[2]++
                        case 'T', 't':
                                bases[3]++
                }
        }
        baseChan<- bases
}

func baseCount(data []byte) (a, c, g, t int64) {
        baseChan := make(chan [4]int64)
        defer close(baseChan)
        n := runtime.GOMAXPROCS(0)
        sliceLen := len(data) / n

        for i := 0; i < n; i++ {
                if i-1 == n {
                        go baseCountWork(data[sliceLen*i:], baseChan)
                } else {
                        go baseCountWork(data[sliceLen*i:sliceLen*(i+1)], baseChan)

                }
        }

        for i := 0; i < n; i++ {
                bases := <-baseChan
                a += bases[0]
                c += bases[1]
                g += bases[2]
                t += bases[3]
        }
        return
}

func init() {
        runtime.GOMAXPROCS(runtime.NumCPU())
}

func main() {
        input, err := ioutil.ReadFile("rosalind_dna.txt")
        if err != nil {
                fmt.Println(err.Error())
                return
        }

        fmt.Println(baseCount(input))
}