mirror of
https://github.com/unknwon/the-way-to-go_ZH_CN.git
synced 2025-08-12 03:06:41 +08:00
111 lines
2.7 KiB
Go
Executable File
111 lines
2.7 KiB
Go
Executable File
// statistics.go
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package main
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import (
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"fmt"
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"log"
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"net/http"
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"sort"
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"strconv"
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"strings"
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)
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type statistics struct {
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numbers []float64
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mean float64
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median float64
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}
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const form = `<html><body><form action="/" method="POST">
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<label for="numbers">Numbers (comma or space-separated):</label><br>
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<input type="text" name="numbers" size="30"><br />
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<input type="submit" value="Calculate">
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</form></html></body>`
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const error = `<p class="error">%s</p>`
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var pageTop = ""
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var pageBottom = ""
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func main() {
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http.HandleFunc("/", homePage)
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if err := http.ListenAndServe(":9001", nil); err != nil {
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log.Fatal("failed to start server", err)
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}
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}
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func homePage(writer http.ResponseWriter, request *http.Request) {
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writer.Header().Set("Content-Type", "text/html")
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err := request.ParseForm() // Must be called before writing response
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fmt.Fprint(writer, pageTop, form)
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if err != nil {
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fmt.Fprintf(writer, error, err)
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} else {
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if numbers, message, ok := processRequest(request); ok {
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stats := getStats(numbers)
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fmt.Fprint(writer, formatStats(stats))
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} else if message != "" {
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fmt.Fprintf(writer, error, message)
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}
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}
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fmt.Fprint(writer, pageBottom)
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}
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func processRequest(request *http.Request) ([]float64, string, bool) {
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var numbers []float64
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var text string
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if slice, found := request.Form["numbers"]; found && len(slice) > 0 {
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//处理如果网页中输入的是中文逗号
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if strings.Contains(slice[0], "，") {
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text = strings.Replace(slice[0], "，", " ", -1)
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} else {
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text = strings.Replace(slice[0], ",", " ", -1)
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}
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for _, field := range strings.Fields(text) {
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if x, err := strconv.ParseFloat(field, 64); err != nil {
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return numbers, "'" + field + "' is invalid", false
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} else {
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numbers = append(numbers, x)
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}
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}
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}
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if len(numbers) == 0 {
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return numbers, "", false // no data first time form is shown
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}
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return numbers, "", true
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}
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func getStats(numbers []float64) (stats statistics) {
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stats.numbers = numbers
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sort.Float64s(stats.numbers)
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stats.mean = sum(numbers) / float64(len(numbers))
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stats.median = median(numbers)
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return
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}
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func sum(numbers []float64) (total float64) {
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for _, x := range numbers {
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total += x
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}
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return
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}
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func median(numbers []float64) float64 {
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middle := len(numbers) / 2
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result := numbers[middle]
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if len(numbers)%2 == 0 {
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result = (result + numbers[middle-1]) / 2
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}
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return result
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}
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func formatStats(stats statistics) string {
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return fmt.Sprintf(`<table border="1">
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<tr><th colspan="2">Results</th></tr>
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<tr><td>Numbers</td><td>%v</td></tr>
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<tr><td>Count</td><td>%d</td></tr>
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<tr><td>Mean</td><td>%f</td></tr>
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<tr><td>Median</td><td>%f</td></tr>
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</table>`, stats.numbers, len(stats.numbers), stats.mean, stats.median)
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}
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