GO语言练习：第一个Go语言工程--排序
1、代码
2、编译
3、运行
1、代码框架 /home/fengbo/sorter
$ tree
.
├── bin
├── pkg
├── readme.txt
└── src
├── algorithms
│ ├── bubblesort
│ │ ├── bubblesort.go
│ │ └── bubblesort_test.go
│ └── qsort
│ ├── qsort.go
│ └── qsort_test.go
└── sorter
└── sorter.go
1.1、src/algorithms/bubblesort/bubblesort.go
//bubblesort.go
package bubblesort func BubbleSort(values []int) { flag := true
for i := 0; i < len(values) - 1; i++ { flag = true
for j := 0; j < len(values) - i - 1; j++ { if values[j] > values[j + 1] { values[j], values[j + 1] = values[j + 1], values[j] flag = false } if flag == true { break; } } } }
1.2、src/algorithms/bubblesort/bubblesort_test.go
//bubble_test.ho
package bubblesort import "testing" func TestBubbleSort1(t * testing.T) { values := []int {5, 4, 3, 2, 1} BubbleSort(values) for i := 0; i < len(values) - 1; i++ { if values[i] > values[i + 1] { t.Error("ubbleSort() faild. Got at ", values[i], values[i + 1]) break } } } func TestBubbleSort2(t * testing.T) { values := []int{5} BubbleSort(values) if(values[0] != 5) { t.Error("BubbleSort() faild. Got ", values, "Excepted 5") } }
1.3、src/algorithms/qsort/qsort.go
//qsort.go
package qsort func quickSort(values []int, left, right int) { temp := values[left] p := left i, j := left, right for i <= j { for j >= p && values[j] >= temp { j-- } if j >= p { values[p] = values[j] p = j } if values[i] <= temp && i <= p { i++ } if i <= p { values[p] = values[i] p = i } } values[p] = temp if p - left > 1 { quickSort(values, left, p - 1) } if right - p > 1 { quickSort(values, p + 1, right) } } func QuickSort(values []int) { quickSort(values, 0 , len(values) - 1) }
1.4、src/algorithms/qsort/qsort_test.go
//qsort_test.go
package qsort import "testing" func TestQuickSort1(t * testing.T) { values := []int {5, 4, 3, 2, 1} QuickSort(values) var i int; var j int = len(values) - 1
for i = 0; i < j; i++ { if values[i] > values[i + 1] { t.Error("QuickSort() faild") break; } } } func TestQuickSort2(t * testing.T) { values := []int {5} QuickSort(values) if values[0] != 5 { t.Error("QuickSort() faild. Got", values); } }
1.5、src/sorter/sorter.go
package main import "bufio"
import "flag"
import "fmt"
import "io"
import "os"
import "strconv"
import "time"
import "algorithms/bubblesort"
import "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 readValues(infile string)(values []int, err error){ file, err := os.Open(infile) if err != nil{ fmt.Println("Failed to open the input file :", infile) return } 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, outfile string) error { file, err := os.Create(outfile) if err != nil { fmt.Println("Faild to create the outfile ", outfile) return err } defer file.Close() for _, value := range values { str := strconv.Itoa(value) file.WriteString(str + "\n") } return nil } func main(){ flag.Parse() if infile != nil { fmt.Println("infile =", *infile, "outfile = ", *outfile, "algorithm = ", *algorithm) } values, err := readValues(*infile) if err == nil { t1 := time.Now() switch *algorithm { case "qsort" : qsort.QuickSort(values) case "bubblesort" : bubblesort.BubbleSort(values) default : fmt.Println("Sorting algorithm", * algorithm, "is either unknown or ensupported.") } t2 := time.Now() fmt.Println("The sorting process costs", t2.Sub(t1), "to complete.") writeValues(values, * outfile) }else { fmt.Println(err) } }
2、编译
2.1、设置环境变量
[fengbo@sorter]$ pwd /home/fengbo/sorter [fengbo@sorter]$ export GOPATH="/home/fengbo/sorter"
2.1编译级安装
$ go build algorithms/bubblesort $ go build algorithms/qsort $ go install algorithms/bubblesort $ go install algorithms/qsort $ go build sorter
2.2、编译及安装后的目录结构
$ tree
.
├── bin
├── pkg
│ └── linux_386
│ └── algorithms
│ ├── bubblesort.a
│ └── qsort.a
├── readme.txt
├── sorter
└── src
├── algorithms
│ ├── bubblesort
│ │ ├── bubblesort.go
│ │ └── bubblesort_test.go
│ └── qsort
│ ├── qsort.go
│ └── qsort_test.go
└── sorter
└── sorter.go
3、运行
3.1、未排序的文本文件
$ cat unsorted.dat 6
345
76564
5
66
443654
757
2365
565
3.2、运行排序程序
$ ./sorter -i unsorted.dat -o sorted.dat -a qsort infile = unsorted.dat outfile = sorted.dat algorithm = qsort The sorting process costs 2.22us to complete.
3.3、排序后的结果文件
$ ls sorted.dat sorter unsorted.dat $ cat sorted.dat 5
6
66
345
565
757
2365
76564
443654
4、注释
代码来源于《Go语言编程》一书的第二章，目录结构与原书有些差异。