update

ch12/ex01.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"log"
+)
+
+type Eight9Hash struct{
+	size int
+	arr [1E8]bool
+}
+
+func main() {
+	eh := new(Eight9Hash)
+	fmt.Println(eh.getNumber())
+	// fmt.Println(eh.getNumber())
+	// fmt.Println(eh.getNumber())
+	// fmt.Println(eh.getNumber())
+	fmt.Println(eh.requestNumber(19727887))
+}
+
+func (eh *Eight9Hash) getNumber() int {
+	r := rand.Intn(1E8)
+	limit := r - 1;
+	if limit == -1 {
+		limit = 99999999
+	}
+	for ; r != limit; {
+		if !eh.arr[r] {
+			eh.arr[r] = true
+			return r
+		} else {
+			r ++
+			if r == 1E8 {
+				r = 0
+			}
+		}
+	}
+	log.Fatal("error: Full Hash set")
+	return 0
+}
+
+
+func (eh *Eight9Hash) requestNumber(n int) bool {
+	return eh.arr[n]
+}