/
sorter.go
113 lines (94 loc) · 2.04 KB
/
sorter.go
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package main
import (
"bufio"
"flag"
"fmt"
"io"
"os"
"strconv"
"time"
)
import (
"sorter/algorithms/bubblesort"
"sorter/algorithms/qsort"
)
var infile *string = flag.String("i", "unsorted.dat", "File contains values for sorting")
var outfile *string = flag.String("o", "sorted.dat", "File to receive sorted values")
var algorithm *string = flag.String("a", "qsort", "Sort algorithm")
func main() {
flag.Parse()
if infile != nil {
fmt.Println("infile =", *infile, "outfile =", *outfile, "algorithm =", *algorithm)
}
values, err := readValues(*infile)
if err != nil {
fmt.Println(err)
} else {
fmt.Println("Read values", values)
t1 := time.Now()
switch *algorithm {
case "qsort":
{
qsort.QuickSort(values)
}
case "bubblesort":
{
bubblesort.BubbleSort(values)
}
default:
fmt.Println("Sorting algorithm", *algorithm, "is either unknown orunsupported.")
}
t2 := time.Now()
fmt.Println("The sorting process takes", t2.Sub(t1), "to complete.")
err := writeValues(values, *outfile)
fmt.Println("Write values", values)
if err != nil {
fmt.Println(err.Error())
return
}
}
}
func readValues(infile string) (values []int, err error) {
file, err := os.Open(infile)
if err != nil {
fmt.Print("Failed to open the input file", infile)
return nil, err
}
defer file.Close()
br := bufio.NewReader(file)
values = make([]int, 0)
for {
line, isPrefix, err1 := br.ReadLine()
if err1 != nil {
if err1 != io.EOF {
err = err1
}
break
}
if isPrefix {
fmt.Println("A too long line, seems unexpected.")
return
}
str := string(line)
value, err1 := strconv.Atoi(str)
if err1 != nil {
err = err1
return
}
values = append(values, value)
}
return
}
func writeValues(values []int, outfileName string) error {
outfile, err := os.Create(outfileName)
if err != nil {
fmt.Print("Failed to create the outfile", outfileName)
return err
}
defer outfile.Close()
for _, value := range values {
str := strconv.Itoa(value)
outfile.WriteString(str + "\n")
}
return nil
}